You’re probably aware of multiple controversial issues surrounding Yelp reviews. There are several to choose from. You have some businesses accusing the company of holding positive reviews hostage (with advertising being the ransom). You have a court ordering Yelp to turn over the identities of anonymous Yelp reviewers. You have people paying other people to write fake reviews, whether it’s negative reviews for competitors or positive reviews for their own business.

Do you find Yelp to be a reliable source of information for consumers? Is your own business fairly portrayed? Ever suspected a review was a fake? Let us know in the comments.

These are all issues that Yelp has to deal with on an ongoing basis, and that consumers have to take into consideration every time they read a review on the site. The fake reviews are apparently so prevalent that the company is ramping up its efforts to combat them.

“Consumers, on average, can rely on the content they see on Yelp,” CEO Jeremy Stoppelman said on stage at LeWeb last year. Reassured?

In the fall of 2012, Yelp revealed a new system for combating fake reviews with its Consumer Alerts. Yelp shows warnings to users when they’ve found businesses that have paid for reviews. If you come across such a business listing, you’re greeted with a Consumer Alert, which explains that they’ve caught someone red-handed trying to buy reviews.

Yelp doesn’t kick the business out of its service, but the embarrassing warning appears on the business listing for three months. Yelp has hoped that this would serve as a deterrent. Just how well it’s actually working remains a mystery. So far, Yelp has reportedly issued 285 of the alerts with more on the horizon.

Stoppleman was interviewed for an article this week by The Telegraph. He talked about how the company is conducting “sting operations,” where Yelpers pose at users willing to write paid reviews. It’s only been happening in the U.S. so far, but is about to be expanded into Europe.

“It has been incredibly successful in that we have been able to catch businesses red handed,” Stoppleman is quoted as saying of the sting operations.

But how successful has Yelp really been at spotting fake reviews? Catching people red-handed is one thing. How many are not being caught?

Yelp has certainly been using the law to go after paid reviews, but a lot of this has been happening well after the Consumer Alerts system was put in place. Last summer, Yelp sued BuyYelpReview.com, obviously for selling reviews (not the latest such suit filed by Yelp).

Apparently Yelp has busted quite a few businesses over the past year. It had already caught nine when it first launched the Consumer Alerts, then launched another round of them in August. With the number approaching 300, it would appear that the program, at least initially, did little to deter the practice (though Stoppleman told the Telegraph it’s “obviously a deterrent”).

“We’ve seen some pretty extreme chicanery in connection with these businesses, including people buying fake reviews, offering rewards or discounts for reviews or having a large number of reviews submitted from the same Internet Protocol (IP) address (a clue that someone may be trying to artificially inflate their rating),” said Yelp VP of Consumer & Mobile Products Eric Singley in August.

In September, a Harvard Business School study suggested that 16% of Yelp restaurant reviews are potentially fake.

Luther Lowe, director of public policy at Yelp, tells us that 16% figure is misleading, as “HBS used reviews Yelp identified as suspicious (not ‘fake’) to run [its] analysis. 25% suppressed not 16%.”

Yelp responded to the study, saying that the findings “shouldn’t come as a complete surprise.”

“As consumers increasingly turn to online reviews to find a local business, the incentive to artificially improve one’s reputation also increases,” the company said. “But neither should the fact that Yelp has been on guard against these very same reviews from our earliest days.”

It went on to talk up its controversial review filter.

That same month, New York Attorney General Eric T. Schneiderman announced that nineteen companies agreed to stop writing fake Yelp reviews and pay over $350,000 of fines.

“Consumers rely on reviews from their peers to make daily purchasing decisions on anything from food and clothing to recreation and sightseeing,” he said. “This investigation into large-scale, intentional deceit across the Internet tells us that we should approach online reviews with caution.”

“We think it’s great the New York Attorney General took action against these businesses that try to mislead consumers. In fact, we helped him,” said Yelp Senior Litigation Counsel Aaron Schur. “Because Yelp uses sophisticated software to filter reviews and weed out less reliable ones, we identify — and take action against — concerted campaigns to game the system quite frequently. As a result, we were able to give the NY AG’s office some solid leads on which businesses to go after.”

“And we have more,” he added. “We would love to work with law enforcement officials in other states to crack down on this unethical practice.”

Meanwhile, there are more reviews being posted to Yelp than ever. In the second half of 2013, Yelp added the ability to review businesses from its mobile apps. Earlier this month, Yelp boasted 47 million reviews, seemingly encouraging the saturation of the site with reviews by recognizing a guy who wrote 1,712 in 2013 alone. Perhaps more reviews means better odds of drowning out the fake ones.

At least Yelp isn’t eager to roll over on fake reviews without significant evidence. Despite being ordered to do so, Yelp has been resistant to handing over the names of anonymous users, whom a business alleges wrote fake negative reviews about it.

How bad is Yelp’s fake review problem? Do you think Yelp is doing a good job of keeping it under control? Share your thoughts in the comments.