As with my reply to monochromatic, I guess the issue here is the definition of the term &quot;patent troll&quot;. People often use the term anytime a patent they don&#x27;t like is asserted. However, studies suggest that patent trolls don&#x27;t assert patents any worse or better than those that practicing entities assert. See for instance, 
<a href="http:&#x2F;&#x2F;papers.ssrn.com&#x2F;sol3&#x2F;papers.cfm?abstract_id=1792442" rel="nofollow">http:&#x2F;&#x2F;papers.ssrn.com&#x2F;sol3&#x2F;papers.cfm?abstract_id=1792442</a> for a limited by illustrative empirical study which also references several other related papers. This study also indicates that NPEs are probably a significant avenue for assertion of patents from individual inventors.<p>I will agree that there is a substantial patent quality problem, with a number of overly broad and poorly-defined patents being asserted by firms, non-practicing or otherwise. However, from my observation over almost a decade, I would also say that this problem is declining rapidly, as most of these patents were issued during a period when the PTO had no idea how to deal with them two decades ago.