These are commonly called "submarine patents". Google it. There was a big deal a few years ago with bar codes being claimed as a patent by a guy who held over 700 patents, but never built anything. The process was to patent something when it was no more than science fiction, then update the patents with follow on patents as technology changed. It almost worked, some of the bar code reader outfits settled, some others fought it and won.
The original bar code submarine patent described (in very vague terms) a "system that uses a televsion or other electronic means to identify an object automatically through the use of a computer or other electronic device". It was actually that vague, and yet somehow was granted a patent.
I am all for the reform of the patent process.