JACKIE JUDD:

The possibilities do seem limitless, especially here in San Francisco, home of the online review giant Yelp.

The number of consumer reviews posted online is mind-boggling. Just in the time that the NewsHour is on the air tonight, some 2,000 reviews will be posted on Yelp alone. That makes the task of identifying deceptive entries, as well as keeping one step ahead of the perpetrators, an ongoing challenge. Yelp is a pioneer in aggregating consumer reviews of local businesses.

Its slogan used to be real people, real reviews. Now, not so much. Yelp labels about 25 percent of submitted reviews as suspicious or not recommended.