Thinking of suing?

First, read over 47 USC Section 230, the federal law which protects providers of interactive computer services from liability for defamatory information posted on the network by someone else.  Under 230(c)(1) "No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider."
 

Does this change when KnowYourProfessor deletes inappropriate comments?

No.  Under 230(c)(2)(A), (2) Civil liability.--No provider or user of an interactive computer service shall be held liable on account of -- (A) any action voluntarily taken in good faith to restrict access to or availability of material that the provider or user considers to be obscene, lewd, lascivious, filthy, excessively violent, harassing, or otherwise objectionable, whether or not such material is constitutionally protected.


Also see:

Zeran v. AOL

Gentry v. eBay Inc.

Schneider v. Amazon.com

Court punishes school for punishing student

Court Extends Libel Protection to E-Publishers (1)

Court Extends Libel Protection to E-Publishers (2)

Still have questions?  Contact us at Legal@KnowYourProfessor.com