• How the Internet Works (And How SOPA Would Break It)
• An Open Letter From Internet Engineers to the U.S. Congress

Section 230 of the Communications Decency Act grants interactive online services of all types, including blogs, forums, and listservs, broad immunity from tort liability so long as the information at issue is provided by a third party. Relatively few court decisions, however, have analyzed the scope of this immunity in the context of "mixed content" that is created jointly by the operator of the interactive service and a third party through significant editing of content or the shaping of content by submission forms and drop-downs.

So what are the practical things you can take away from this guide? Here are five:

1. If you passively host third-party content, you will be fully protected under Section 230.
2. If you exercise traditional editorial functions over user submitted content, such as deciding whether to publish, remove, or edit material, you will not lose your immunity unless your edits materially alter the meaning of the content.
3. If you pre-screen objectionable content or correct, edit, or remove content, you will not lose your immunity.
4. If you encourage or pay third-parties to create or submit content, you will not lose your immunity.
5. If you use drop-down forms or multiple-choice questionnaires, you should be cautious of allowing users to submit information through these forms that might be deemed illegal.

Editing of content that materially alters its meaning. If you edit content created by a third-party and those edits make an otherwise non-defamatory statement defamatory, you will likely lose your immunity under Section 230. Where this line is, however, remains unclear. Obviously, if you remove the word "not" from a sentence that reads "Jim Jones is not a murderer," you will have substantially altered the meaning of the sentence and made an otherwise non-defamatory statement defamatory.

A website operator may take an active role in editing content, whether for accuracy or civility, and it will still be entitled to Section 230 immunity so long as the edits do not substantially alter the meaning of the content (i.e., make an otherwise non-defamatory statement defamatory). In an interesting case involving New Jersey politics, Stephen Moldow ran a website and forum where users criticized local elected officials. Muldow regularly deleted offensive messages, gave guidelines for posting, and edited and re-posted messages to remove obscenities. Although the plaintiffs argued the Moldow participated in the creation of the defamatory content and should therefore be held liable, the court concluded that Moldow's activities were nothing more than the exercise of traditional editorial functions and thus immunized under Section 230. Donato v. Moldow, 865 A.2d 711 (N.J. Super. Ct. 2005).