Sibel Edmonds alleges that the FBI collected information about the lesbian affair of a Democratic Congresswoman. That is a bombshell accusation, one I'd hazard would be more newsworthy to most people in the US than the Snowden disclosures.

Why can I only find references to that allegation on sites like LewRockwell.com, and not on WaPo or the NYT?

I have absolutely no clue. But that's a weird one, especially since it never resulted in any kind of fall-out either way. You'd take that those accusations would not be left to stand without a solid rebuttal.

...unless they were very obviously made up and the person making them of little public importance, in which case it would probably be more damaging to even acknowledge them as being worth discussion.

That was testimony under oath. If it was false testimony the penalties would be grave which somewhat reduces the chances of it being 'obviously made up'.

Of note, her allegation regarding blackmailing a congresswoman was against Turkish agents whom the FBI was wiretapping, not the FBI themselves. In her deposition she specifically says

> [...] information was being collected for blackmail purposes, and her lesbian relationship, and they, the Turkish entities, wanted both congressional related favoritism from her, but also her husband was in a high position in the area in the state she was elected from, and these Turkish entities ran certain illegal operations, and they wanted her husband's help. But I don't know if she provided them with those. I left. I was terminated.

The penalties for lying under oath are usually anything but grave. Moreover: to punish her, the state has to prove that she knowingly lied. But I believe she believes what she's saying. That doesn't mean she's right.

Very good question... Daniel Ellsberg wrote about a related story that was front page "London's Sunday Times" [1] and various foreign press. But searching Google for 2008-2010 there is zero mainstream American news coverage of that story or the 2009 deposition. Yet they covered her earlier whistleblowing heavily between 2002-2004.

[1] http://www.huffingtonpost.com/daniel-ellsberg/covering-up-th...

Edit: upon further reading it appears to not be an allegation against the FBI but rather Turkish agents which makes this much less news-worthy:

> Turkish agents started gathering information on her, and they found out that she was bisexual. So a Turkish agent struck up a relationship with her. [ ... ] I don’t know if Congresswoman Schakowsky ever was actually blackmailed or did anything for the Turkish woman. http://www.bradblog.com/?p=7429