Apple is in a curious position when it comes to patents. It owns piles of them, and its lawyers regularly deploy them to beat the stuffing out of rival Samsung.

But Apple AAPL has also filed way more challenges than anyone else at the Patent Trial and Appeal Board, a controversial body where companies can try to knock out patents they view as invalid.

According to a new report by legal analytics company Lex Machina, Apple filed 252 so-called PTAB challenges since September of 2012, which is nearly 100 more than the second top filer, Samsung ssnlf . The next most active challengers were Google googl , then LG, then Microsoft msft .

Why does all this matter? It matters because in recent years the PTAB has become a hotbed of activity thanks to a law that makes it easier for companies to challenge patents. Critics have likened the PTAB to a death squad for patents, and a means for big tech companies to steamroll small inventors.

But many others argue that the judges of the PTAB are just applying common sense in kiboshing patents that should never have been granted in the first place. The forum has also been hailed as a useful weapon against a plague of “patent trolls,” which are shell firms that acquire old patents in order to badger companies with nuisance lawsuits.

The high profile of Apple at PTAB may provide more grist for this debate since the company is not shy about asserting its own intellectual property, including in a closely watched case with Samsung up for review by the Supreme Court. Apple has also been less vocal than other Silicon Valley companies in calling for patent reform.

Apple did not immediately reply to a request for comment.

According to Brian Howard, Lex Machina’s chief legal scientist, the report also serves to rebut “alarmist conclusions” about the PTAB’s activities. He pointed to the chart below to show that the board is far from a death squad, and that challengers win only 23% of the time:

PTAB data

Howard says misperceptions about how often the PTAB invalidates patents arise because critics don’t acknowledge that many of the challenges fail at the “institution stage”—meaning the board just throws out the challenges without a formal hearing. He explained that Lex Machina published the report to show off its analytic tools.

These tools include data about judges’ experience, the different types of patent challenges and the types of patents being challenged – those related to communications and semiconductor turn up at PTAB most often, while those in the mechanical engineering and biochemistry categories are more rare.

“Lex Machina felt there wasn’t a lot of clarity as to what was going on in PTAB,” Howard says. “This reports fits into the long-term desire to show people what you can do with this data, and to inform the controversy as to what role PTAB is playing in the patent word.”

For more about patent policy, see Fortune’s interview with N.Y. Sen. Chuck Schumer about patent trolls:

The PTAB is about to get more scrutiny still in light of the Supreme Court’s recent decision to hear a case about how an appeals court should review its decisions.