Google is more likely than not to buy Yelp, say news reports. Which raises one glaringly obvious question: Will Google exacerbate or correct the local review site's worst tendencies, which have brought extortion allegations, porny bacchanals and physical violence?

Google is in advanced talks to pay around $500 million for Yelp, according to a story from TechCrunch confirmed by the New York Times, which described the talks in straightforward business terms: "Google has been showing greater interest in the local business market in the United States."

But Yelp isn't just any online content startup. It wields disproportionate power over local merchants, from restaurants to auto body shops, and said merchants have repeatedly told tales of Yelp offering to let them re-arrange reviews if they took out ads — and of disappearing positive reviews in retaliation when they complained about the ethics of the situation. The San Francisco-area alt-weekly East Bay Express ran a series of articles on such practices, and the story eventually went national.

One business owner got so frustrated with Yelp users — and Yelp Inc.'s passive aggressive handling of her — that she ended up in a wrestling match with a reviewer she had flamed on email.

The company is also known for its raging, drunken, fleshy user parties, which are thrown, alternately, by the company itself and by the restaurants subject to its users' reviews.

Google has already seen its reputation as the "Don't Be Evil" internet company erode significantly, most recently after CEO Eric Schmidt said people should consider not having secrets, a story that spread widely online and in the news media. If it's going to seduce Yelp, Google should make sure its remaining friends know the company plans to reform its new toy rather than join its caddish pursuits.

(Top pics: Yelp co-founder Russel Simmons has fun with an employee at a Yelp holiday party, from this Valleywag post.)