A case headed to the Virginia Supreme Court could bring still more scrutiny to review site Yelp, which has been trying to protect the anonymity of its users despite subpoenas for the names of reviewers who have punished businesses listed on the site.
"It's this age-old fight between protecting your users who want to remain anonymous and working with companies that are potentially your customers ... companies that Yelp wants to buy advertising on the site. They're kind of stuck between a rock and a hard place," said CNET Senior Editor Dan Ackerman.
"Sites like Yelp, Citysearch, etc. have a mechanism for flagging a review, but some businesses will use that to unfairly hide negative criticism," Ackerman said.
Read MoreForget lawsuits—Yelp's going higher, says analyst
Yelp has refused to give up the names of reviewers who one business owner said are to blame for a 30 percent decline in traffic, which led to 80 layoffs at his company, according to The Wall Street Journal.
—By CNBC's Althea Chang