Think the Internet is a fun free-for-all where you can say whatever you want? Think again. The world of blogs and social-media sites may feel like the Wild West, but it has rules, and breaking them can hit you right in the cash register.

Consider the case of Cretella vs. Kuzminski. The case began when Christine Norris of the Web site Absolute Write referred to vanity publishing company PublishAmerica as "a scam" in her online forum comments. Visitors to the forum, including David Kuzminski of the site Preditors and Editors, posted other negative statements about PublishAmerica. The company's lead counsel sued Kuzminski for defamation, and in Feb. 2009 a jury awarded PublishAmerica $236,000 in damages.

As the Kuzminski case shows, shooting your mouth off on the Internet can really cost you. In fact, content published on the Internet has always faced the same legal standards as published material in newpapers and magazines, says New York City attorney Nina Kaufman, whose own site is Ask The Business Lawyer.

A top no-no is simply making stuff up about people or companies. This is the defamation problem Kuzminski ran afoul of in the Cretella case.

"If you write something that is totally false and can harm someone's reputation," Kaufman says, "that could result in a defamation claim."

The next issue to consider is copyright. It's easy to cut and paste interesting articles or photos from someone else's Web site, but doing it leaves you open for a copyright claim. The area is a little vague because there is a "fair use" clause which allows publishers to use excerpts from others' materials without payment. Exactly how much you can use isn't spelled out in the law, Kaufman notes. If you use perhaps a paragraph of another author's work and add your own thoughts and comments, you're probably in the clear. Always safe: put your comments on your site and then provide a link to the original material.

One tip for those who'd like to protect their own blogs from being ripped off: Occasionally, print out all your blog entries, fill out a copyright application and send the bundle off to the U.S. Copyright Office. While copyright attaches at creation, having the Copyright Office paperwork will strengthen your case if you want to sue someone for reproducing your blogs without payment or permission.

New rules for reviews, ads and endorsements

Recently, the Federal Trade Commission (FTC) issued new rules that bolster existing law regarding online advertising or product reviews. As in the past, you should not be making misleading or false statements in any advertising or blogs where you review or discuss products.

The new twist: bloggers must disclose if they received the product free or if they were paid to write about the product.

"If you're talking about how wonderful these golf balls are and you don't tell me you're being paid $5,000 to give your endorsement, that really affects whether I choose to buy or not," says Kaufman.

Another new wrinkle: if an endorser approved one version of your product, but now you've changed the formula, the endorser must be contacted and given a chance to review the new formula and decide if they will still endorse it. You can't just keep slapping your pitchman's face on ads for new products or formulations.

One last, critical area for online advertisers concerns the type of claims you can make about a product. In the past, if you found one person who lost 100 pounds using your herb formula, you could use them in an ad and simply include a "results not typical" disclaimer. That is no longer acceptable, says Kaufman. Ads must now demonstrate typical results for your product. Hard facts, not one or two anecdotal cases, should support your claims.

"If you're using social media as part of your marketing strategy to promote your product, you have to be clear on what is going to substantiate your claims," Kauman says. "Have you done a survey? Be ready to back up your claims."

To stay on the right side of online blogging, social media and advertising law, follow the FTC's advice from its Fact Sheet: Advertising must tell the truth and not mislead customers. Claims must be substantiated.

For instance, if you used a hand lotion and noticed that it cured your excema, that's exactly what you should say. Kaufman notes that if you write instead "Wow, this hand lotion cures excema," you could be opening the door to a lawsuit for making false and misleading statements.

To learn more about your rights and responsibilities when you're blogging and using social media, visit this Blogger Law entry on 12 Important U.S. Laws Every Blogger Needs to Know