Factual error: At the start of the film, they are using an optical telescope for astronomy in daylight. This is not possible. The telescope is also far too small to be giving such a detailed picture.
Factual error: In the scene when Maggie goes to the building rooftop to set a listening device to eavesdrop on Anton and Linda, she sets up what is presented as a parabolic microphone. However, the device she sets up is actually a radio frequency (RF) micro-wave style antenna that would be used for point to point RF communication. An audio parabolic microphone would be a round, solid dish shaped design to reflect the audio waves to a highly sensitive microphone at the focal point of the dish. The RF antenna used in the film would not capture any audio.