The FBI Special Support Group , or SSG (They're nicknamed G's), supposedly does much of the routine  work for the Bureau, leaving the FBI agents themselves free to pursue more important matters.
The SSG works in teams of five or more, "keeping tabs" on known and suspected criminals
and more recently, suspected terrorists who are under surveillance.
They carry notebooks to write down information about the subject(s), like where they went,
how long they stayed there, and any suspicious activity they may observe.
Many carry small voice recorders to take notes on-the-fly.
There is a Team Leader, a SSG member who has been promoted to the rank, who keeps order
and assigns various tasks to the G's on the team.
Hand signals are very important, and are the traditional means of silent communication
amoung SSG's, although they now often employ cell phones and radios when applicable.
In case a dangerous situation developes, and to call all the G's to leave the scene and 
gather at a pre-designated location, the Team Leader waves a white handkerchief.

Special Support Group members are not official FBI agents, have no powers of arrest, nor 
are they authorised to carry weapons unless they're retired or off-duty Law Enforcement 
personnel.They are chosen, usually by application, recommendation and sometimes recruitment,  from the general population.  Housewives, office workers, college students - people from 
every walk of life work for the SSG.

They usually work part-time, and earn about $5,000.00 - $10,000.00 per year or more.

The FBI doesn't advertise the existence of the SSG, but it's no big secret either.

The reality of the Special Support Group is much different than the "released" information.

SSG teams regularly harrass and even menace people on the FBI's Black List.
They engage in psychological warfare against their targets. They often dress up like
children on Halloween, and follow and harrass people like a travelling circus of clowns and freaks.
Much of the time they travel in LARGE groups of two dozen or more, rather than the small teams originally written about in the media years ago.
(I haven't seen anything in the media about them in recent years, but rest assured, they're out there.)

The FBI calls this harrassment "dangling," and they do it on a regular basis to people who
frequently have committed no offense other than to have drawn the ire of the Bureau.

Many SSG's are of the lowest caliber of human life, especially those chosen for excessive
harrassment of innocent citizens.
Far too often SSG teams consist of bullies, perverts, racists and ex-convicts and other dregs whose sole purpose is to drive people crazy and ruin their lives.
If one of their victims snaps and tears one of them up, the bloodied G will press charges, perjure himself if confronted with his FBI affiliation, and the victim is locked up. Mission accomplished.

That's one reason why the FBI is not very open about the SSG.

This is just one of the many questionable and outright illegal activities that the FBI
uses our tax dollars for.
The very people sworn to uphold our Civil Rights are perhaps the most flagrant violators.

If you attend a protest rally, or otherwise call attention to yourself, don't be surprised
if you start seeing the same bizarre group of people showing up everywhere you go, bothering
you and behaving like psychotic clowns.