One of the problems with patent enforcement: the patent holder has the right, but not the obligation, to pursue infringement. Or in plain English: they can pick their fights.
If IBM, Mac's Komputer Shoppe, and Western States Services, Inc. all infringe, odds are good that the PatTrollCo will skip IBM (able to defend) and Mac (no assets) but nail WSS (big enough to have assets, not big enough to have attorneys on retainer or a significant patent portfolio).
A string of these small victories makes it much easier for them to shake down the big targets later... So while you PROBABLY won't be the target of a lawsuit unless you're very successful, there's a bit of a lottery that happens pretty often with these cases where some small percent of small targets do get run over by the patent holders on the road to the bigger guys. And if you happen to draw the short straw on that, it sucks to be you.