Wikipedia: "Surveillance is the monitoring of behavior, activities, or information for the purpose of information gathering, influencing, managing or directing.

Wikipedia: "Surveillance is the monitoring of behavior, activities, or information for the purpose of information gathering, influencing, managing or directing." Which I think most would agree is the standard definition of surveillance, and I also think the concept of being surveilled comes naturally to most, which is why parties that surveil people make clear efforts to obfuscate the fact that they do so.