Abstract: A NAT system is identified as operating in conjunction with a specific IP address, in response to a threshold number of different authenticated computing devices making requests to the web service from the specific IP address during a given time period. The total number of computing devices operating from behind the identified NAT system is estimated, based on how many separate authenticated computing devices make requests to the web service from the IP address during the period of time. When a NAT system is identified, one or more additional action(s) are taken to manage the processing of traffic originating from the specific IP address, taking into account that multiple computing devices are operating behind the identified NAT system. An example action is rate limiting.

Abstract: The disclosed computer-implemented method for logging users out of online accounts may include (i) receiving, from a first computing device of a user, a request from the user to log into an online account hosted by an online platform, (ii) establishing, between the online platform and a second computing device of the user, a network session that both (a) verifies the identity of the user to the online platform and (b) at least partially disrupts the functionality of the second computing device, (iii) logging the user into the online account via the first computing device, (iv) detecting a request from the user to log out of the online account, and then (v) in response to the request to log out of the online account, (a) restoring full functionality of the second computing device by terminating the network session and (b) logging the user out of the online account.