Sorry to say this as I have a number of very good American friends but lawsuits and patent infringements seem to be something that originates from the USA a lot more than in other countries.
I know this from first hand experience many years ago, long before patent trolls were around. I worked for a company in Scotland who was developing at the time, a telematics system which was quite ahead of its time back then. Through a government funded initiative to expand our company overseas we where invited to a meeting in Dallas to which we got interest from a local company looking to build just such a system for their clients to support their servicing venture.
Anyway, we met a few months later and we did a demo and came up with a specification for their needs. We took some data from them to include in their version of the app and returned to Scotland to develop it for them. During this time we sent various images to show them the look and accidentally our web designer put one of the images on our website. It was a genuine mistake but the US company decided to take us to court for using their logo in our advertising. It cost the company thousands to deal with this as they had to go to the US to sort it out. We came to the conclusion during this that the company was struggling financially and saw this as a way to make some money but it was eventually won by my company but not before we lost a lot of our money and in the end the company was forced to go out of business and I lost my job.
So based on this, patent trolls and lawsuits are not my cup of tea, as they say. I am all for protecting your rights and your designs but doing so just for the money is not.
Sorry for the long winded post on this.