Many of us check online reviews of restaurants or businesses before we try them, and many of us have written a few of those reviews too. But legal experts say it’s important to be careful what you write, because a nasty comment left on a review site could land you in court.

There have been many cases in recent years of companies suing online reviewers for defamation or libel -- often successfully.

Just recently, an Edmonton man told CTV News that a local tech company had threatened him with a six-figure lawsuit after he posted a negative review of the business on Google. He said that the business ordered him to remove the review, or face the prospect of a $150,000 defamation lawsuit. He was refusing to pull the review, however, saying he shouldn’t be penalized for being honest.

Jeff Orenstein, a lawyer with the Consumer Law Group in Montreal, says the definition of libel includes public internet postings that “defame” another – meaning any communication that tends to lower the esteem of someone in the eyes of a reasonable person.

So, how can you ensure your online reviews don’t verge into defamation territory? Orenstein offers these pointers:

1. Don’t assume that trying to stay anonymous, by using a nickname or alias on your reviews, will protect you from a lawsuit. Many courts have ordered ISPs, or internet service providers, to hand over the IP addresses of anonymous online reviewers so that they could be identified and taken to court.

2. Give your opinion and only state facts that you can back up. For example, if you give a restaurant a two-star review because you didn’t like the food, that’s an opinion. But if you say there were cockroaches on the floor, you might be called upon to support your allegations with evidence.

3. Review only the product or service, not the character of the person who provided it, “because that usually ends up being problematic,” says Orenstein.

4. Be truthful, not malicious or vindictive. If you are filled with rage from a poor experience with a business, take 24 hours to cool off before writing your review.