It's silly that it's a valid concern.
So, is this a valid concern, or just silly?
A few years back, someone claimed to have invented spherical texture mapping and went after the entire industry.
SCO claimed to have patents on everything in Linux and tried to extort every one who even knew Linux existed.
Creative Labs went after John Carmack over his shadowing algorithm during the making of Doom 3. They held the project hostage, and I believe, made him include functionality for their new (and useless at the time) sound card.
Those who can, create
Those who can't, litigate
We're all liable to be litigated at some point. Someone will claim to have invented something in C++'s runtime, and try to extort 1000$ out of everyone who ever installed Visual C++ or GCC. That's just the way it is.