Companies that hold crucial patents look at patent trolls and sneer. But then again, Apple Inc. General Counsel Bruce Sewell likely looks at all those other companies and says those companies have it easy.

According to PatentFreedom, a service that helps targeted companies escape patent trolls, Apple has been on the receiving end of 171 separate patent troll lawsuits over the past five years – the most patent troll suits faced of any technology company by nearly 25 percent.

Second on PatentFreedom's list is the Hewlett-Packard Company, with 137 patent troll suits. Samsung Electronics Co., AT&T Inc. and Dell Inc. round out the top five.

Apple has faced numerous IP challenges over the past couple years, both from patent trolls and elsewhere. Currently, the company is fighting back against the Department of Justice for its e-book antitrust suit, claiming the DOJ's regulations put the company at a competitive disadvantage in the e-book market. Apple is also engaged with Samsung over the latter's perceived IP infringement on various cell phone technologies, leading to the ITC's recent ban on the sale of some Samsung products.

Speaking at an All Things D conference earlier this year, Apple CEO Tim Cook spoke disparagingly of these patent troll suits. “It's maddening. It's a waste. It's a time suck,” Cook said. “Does it stop innovation? Well, it's not going to stop us, but it's overhead. I wish we could settle this stuff.”

For more about Apple's legal troubles, check out these InsideCounsel stories: