Abstract: An electronic theft-preventing system, including a first and a second multi-axis magnetometer and configured to output first and second vector signals representing movement of first and second magnetic field vectors; and a signal processor receiving the first and second vector signals, and configured to determine a multi-dimensional transformation, in accordance with optimization of a difference between the second vector signal and a compensation signal; wherein the compensation signal is generated from a transformation of the first vector signal in accordance with the multi-dimensional transformation; and generate a compensated second vector signal from the second vector signal and the first compensation signal. Determining that a detector signal meets a predefined criterion; and in response to at least the determining that the detector signal meets the predefined criterion, raising or forgo raising an alarm that warns about a possible theft-related event.