Legal Complaints against sci.math?


When browsing sci.math with Google Groups tonight, the following
sentence appeared at the bottom of one of the pages:

In response to legal complaints we received, we have removed some
messages. If you wish, you may read the legal complaints.

and there was a link to http://www.chillingeffects.org/notice.cgi?sID=3809
..

So ... Who? What? When? Why?

Any ideas?

--- Christopher Heckman

.