I'll say it again, I'm not saying that PTSC is a troll. I'm not even sure that "patent troll" can be legally defined, or if it matters.

But this article is an interesting read.

For entire article see http://www.bbc.co.uk/news/technology-23673383

Below are a few excerpts that deal with the definition of troll. The last excerpt is most interesting.

"A patent troll is someone who buys patents and then sues people," explains Alan Schoenbaum, general counsel at the cloud computing firm Rackspace, which has been targeted by patent lawsuits."

"Generally they are not inventors, they're entrepreneurs or finance people."

"The majority of patent lawsuits today are filed by entities that don't make any products, in other words in your terminology by patent trolls," ... "Their business model is based on extracting money from those who do make products."

"They play on that fear that the defendant is going to spend a lot of money to defend itself and it is simply cheaper to pay them off."

"When they do reach a deal with their targets, there is almost always a non-disclosure agreement, and the whole process is so shrouded in secrecy that it is difficult to find out what is going on."