Valve wins legal battle against patent troll Rothschild and associated companies
(www.gamingonlinux.com)
80% of patent work is coming up with ideas and filing them. The remaining 20% is ensuring there's no prior art, prior patents, etc.
Besides, patent trolling is not completely negative. The silver lining is that the same system that allows this, also allows e.g. Sony to perpeetum own the patent for interactive TV ads that require the user to yell a word at the TV to ensure they're watching the ad. Sony owns the patent but never implemented it, nor did they license it to others.
Now imagine what would happen if you had to implement your patent into a commercial product or lose the rights to it...