There are law firms out there scanning blogs and forums looking for reposts of copyrighted information.
http://www.techdirt.com/blog.php?company=righthaven&edition=techdirtThey skip the traditional process of sending a DMCA takedown letter, instead opting for a direct lawsuit in federal court. Since few blogs can afford a federal court case, the blog in question will simply settle out of court.
It's extortion, but what can you do?
In the past, courts have found that "fair use" of copyrighted information;
Notwithstanding the provisions of sections 17 U.S.C. § 106 and 17 U.S.C. § 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include:
the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
the nature of the copyrighted work;
the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
the effect of the use upon the potential market for or value of the copyrighted work.
http://en.wikipedia.org/wiki/Fair_use#Fair_use_under_United_States_lawThe most widely held guideline that I can find is to limit cut and paste discussion to four paragraphs for use "as criticism, commentary, news, research, and educational purposes"
I'm probably the worst offender, so I'll try to comply.
GHTalk probably couldn't defend itself against a frivolous lawsuit, I think the best we can do is to not make it easy for them.