Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: Advertisement content presented to a user of an online system is presented along with an option allowing the user to view one or more reasons for presentation of the advertisement content to the user. If the user selects the option, based on targeting criteria associated with the advertisement content and characteristics associated with the user, the online system selects one or more characteristics of the user satisfying the targeting criteria and presents a description to the user identifying the selected one or more characteristics satisfying the targeting criteria. The online system may apply one or more rules based on user perception of characteristics when selecting the one or more characteristics included in the description. An option for the user to prevent use of the selected one or more characteristics when the online system subsequently selects advertisement content for the user is also presented with the description.

Abstract: In particular embodiments, a computing device accesses a device identifier that is encoded in the hardware of the computing device. The device identifier is used to generate a device key that will uniquely identify the particular computing device. The computing device stores the device key in a data store, and sends the device key to be stored on a first computer server. The computing device subsequently requests a user action from a second computer server, and the second computing server requests user authentication. The computing device generates a first authentication code using a cryptographic hash algorithm and the device key, and sends the first authentication code to the second computer server. The computing device is authenticated based on a second authentication code generated by the first computer server using the device key.

Abstract: In one embodiment, a method includes accessing one or more short-message service (SMS) messages received at the first mobile device from a server of a verification authority; automatically and without manual user input, processing by the application data in the SMS messages to detect a particular bit sequence; and automatically and without manual user input, transmitting the information of the first user to the verification authority from the first mobile device in response to detecting the particular bit sequence.

Abstract: An online system receives a content item from content providers and a target audience criterion and for targeting the received content item. The online system determines recommendations of modifications of the target audience criteria such that users of the modified target audience criteria have a higher likelihood of interacting with the content item compared to the received target audience criteria. The online system stores measures of interest of subsets of users for different topics. The online system determines topics associated with the content item and determines measures of interest of subsets of users in the content item based on topics associated with the content item. The online system provides recommendations for modifying the target audience criteria based on the determined measures of interests of users.

Abstract: In particular embodiments, a computing device accesses a device identifier that is encoded in the hardware of the computing device. The device identifier is used to generate a device key that will uniquely identify the particular computing device. The computing device stores the device key in a data store, and sends the device key to be stored on a first computer server. The computing device subsequently requests a user action from a second computer server, and the second computing server requests user authentication. The computing device generates a first authentication code using a cryptographic hash algorithm and the device key, and sends the first authentication code to the second computer server. The computing device is authenticated based on a second authentication code generated by the first computer server using the device key.

Abstract: In particular embodiments, a computing device accesses a device identifier that is encoded in the hardware of the computing device. The device identifier is used to generate a device key that will uniquely identify the particular computing device. The computing device stores the device key in a data store, and sends the device key to be stored on a first computer server. The computing device subsequently requests a user action from a second computer server, and the second computing server requests user authentication. The computing device generates a first authentication code using a cryptographic hash algorithm and the device key, and sends the first authentication code to the second computer server. The computing device is authenticated based on a second authentication code generated by the first computer server using the device key.

Abstract: In one embodiment, a method includes receiving from a mobile device of a user configuration data of the mobile device. The configuration data identifies one or more characteristics of the mobile device. The method also includes determining a group of users of the social-networking system based at least in part on the configuration data. Each user in the group of users uses a mobile device having similar configuration data as the mobile device of the user. The method also includes providing user-assistance information associated with the group of users to the user.

Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: An online system receives a content item from content providers and a target audience criterion and for targeting the received content item. The online system determines recommendations of modifications of the target audience criteria such that users of the modified target audience criteria have a higher likelihood of interacting with the content item compared to the received target audience criteria. The online system stores measures of interest of subsets of users for different topics. The online system determines topics associated with the content item and determines measures of interest of subsets of users in the content item based on topics associated with the content item. The online system provides recommendations for modifying the target audience criteria based on the determined measures of interests of users.

Abstract: Particular embodiments may receive and log information related to one or more events occurring on one or more client computing devices associated with a user. An event may comprise a restriction of a user action on a social-networking system, the restriction comprising the social-networking system blocking the user from performing the user action. An event may comprise a login issue associated with logging in to the social-networking system. An event may comprise a system or device error. System errors may comprise events originating from a third-party system. For each event, an indication of the event and at least one user-activatable reference may be provided for display to the user. A control action may then be determined for the event in response to a user selection of the user-activatable reference. An interface may provide third parties with a view of a user's events as well as functionality to effect control actions.

Abstract: A social networking system performs account recovery for a user with the help of the user's connections (e.g., friends). The social networking system selects connections of the user based on information indicating likelihood of real-world interactions between the user and the selected connections. Access codes are sent to the selected connections and the user instructed to obtain access codes from the selected connections via a communication that is outside the social networking system, for example, via phone. The user provides the access codes obtained from the selected connections to the social networking system. If the access codes provided by the user match the access codes sent to the selected connections, the user is granted access to the account. Real-world interactions between two users are determined based on sharing of devices between the users or information indicating presence of the users in the same place during same time interval.

Abstract: A user makes a request to restrict targeted advertising through third party services accessed on a client device. A publishing system obtains information indicating that the user requested to restrict targeted advertising. The publishing system updates a profile associated with an account of the user to indicate that the user has requested to restrict targeted advertising.

Abstract: An online system determines whether a request for creating a session with the online system is suspicious. The online system associates a user account with a mobile key of a mobile device and geographical locations of the mobile device. The mobile key comprises unique identifier of the mobile device that is permanently stored on the mobile device. Upon receiving a request to create a session for the user account, the online system compares information associated with the user request with information describing the mobile device. For example, information associated with the user request can be a location determined by mapping internet protocol addresses obtained from the request. The online system determines whether the request is suspicious based on the comparison. If the online system determines that the request is suspicious, the online system may require enhanced authentication before granting the request.

Abstract: In particular embodiments, a computing device accesses a device identifier that is encoded in the hardware of the computing device. The device identifier is used to generate a device key that will uniquely identify the particular computing device. The computing device stores the device key in a data store, and sends the device key to be stored on a first computer server. The computing device subsequently requests a user action from a second computer server, and the second computing server requests user authentication. The computing device generates a first authentication code using a cryptographic hash algorithm and the device key, and sends the first authentication code to the second computer server. The computing device is authenticated based on a second authentication code generated by the first computer server using the device key.

Abstract: In particular embodiments, a user associated with a user account wishes to utilize their computing device to facilitate authentication of their identity. The user may provide a device key to an online system hosting the user account, wherein the device key uniquely identifies their computing device. The device key may be based on a device identifier encoded in hardware of the computing device. The online system may then store the device key in association with the user account. Subsequently, if an action related to the online system requires authentication, the user may be asked to provide authentication using their computing device. The user generates an authentication code using their device, which can be entered by the user into a user interface for comparison against an authentication code generated using the device key stored by the online system.