Reply #219: read the OP again -- he used textual analysis

[Ms. Clio]

He traced the FReak's use of a specific, distinctive phrase, and found him using it under both his own name and his handle at the Repuglick.

Further examination of his posts under several different names strongly indicates that they are all the work of the same seriously-disturbed individual.

On edit: I would add that this is an established technique that has been used to "out" the author of at least one anonymously-published book.