J. Edgar started that philosophy in the F.I.B. to gather dirt and leverage it on individuals.

Rumor has it, he did it initially to protect his homosexuality that he hid from the public. Who knows.

All that I've read is that it is still a continued practice at the FBI to "build cases". I am sure we all have a file already started on us all. Only to be used depending on which way the political wins blow.