Consider a scenario involving a full-blown surveillance: email monitoring, cellphone monitoring, online activity monitoring, credit card monitoring, bank account monitoring, and also, 24x7, door-step, snitching-neighbors.
Also consider that the target of this surveillance is a vanilla, boring, life-long law-abiding citizen, with no criminal-record whatsoever.
How high is the bar to allow for such surveillance to target such individual? Is it lawful? Is it abuse of power?
The standard is different for some of the kinds of surveillance described than others.
24x7, door-step, snitching-neighbors doesn't require any justification at all, except to convince someone that the time and money is worth it. It is not, in a constitutional sense a "search".
Cell phone monitoring (meaning wiretapping) requires a sworn statement demonstrating probable cause to believe that is a crime has been, or is in the process of being, committed.
In the alternative, if the surveillance involves a non-U.S. person, and the motive for doing so is espionage, pretty much all that an intelligence agency has to do is say that it is interested.
