There's been interesting reaction to the new FTC rule, starting Dec. 1, that bloggers must disclose receipt of free samples and/or payment.
Check out "Blogged and Sold" by Choire Sicha in the New York Times, saying "The F.T.C.'s misguided effort to regulate online endorsements. Choire makes some good points about the challenges bloggers will face.
Also interesting article about libel laws and Twitter, "Short Outbursts on Twitter? #Big Problem." Bottom-line: don't defame, people.