- you will be expected to report on what other people, including your friends, said or did. Even if they are not doing anything illegal FBI might want information to pressure them into being an informant.
I wasn't in a situation like that, but I expect it would have a huge chilling effect on me - I'd start self-censoring interactions with others our of fear they mention something benign, but gray area legally that I would laugh at otherwise, but now would be required to report and get them in trouble.
This wouldn't have to be something big - I'm sure at some point in time a friend of yours recommended a movie or a tv show that isn't available in your region, implying they have pirated a copy. Would your first reaction be to notify FBI?
> INTERVIEWER: Tell me a little bit about how you felt about working for the FBI. What motivated you and what you thought you were, what ends you thought you were serving?
> WILLIAM O'NEAL: Well, in my community, the policemen were, I mean, it was the quickest way to gain respect. I mean, I think I grew up wanting to be a policeman, admiring and respecting policemen, although I always thought it was outside of my reach. I, my neighborhood was not unlike most people that grew up in Chicago, most young people, we were very mischievous and did a lot of juvenile-type, petty, criminal-type things, but stealing a car and all of a sudden having the FBI, having a case with the FBI, the thought of be--having, really going to jail got my attention. And, so when he asked me to join the Black Panther Party, and he used terms, he never used the word informant. He always said, "You're working for me," and I associated him as the FBI. So all of a sudden I was working for the FBI, which, in my mind, at that point, I associated with being an FBI agent. So I felt good about it. I felt like I was working undercover for the FBI doing something good for the finest police organization in America. And so I was pretty proud.
http://digital.wustl.edu/e/eii/eiiweb/one5427.1047.125willia...
colloquially called "Brownshirts"
Also terrible fashion tastes.
Plus then you're on the government's radar and they think you're money-motivated, not patriotism-motivated. Everyone involved in any cases brought with your help will think poorly of you. This might turn into cases brought against you. You will never get a government job. Your identity will probably be exposed as an informant at some point -- usually through public court records.
If you actually are patriotism-motivated, go join the agency. There is no upside to informing on people.
At first, I thought the boy who was informing was with the good guys taking down drug kingpins. By the end of it, I realized the FBI were just manipulating and using up this young kid.