There are some parts of software where I’m generally aware of patent issues, like media formats and encoders/decoders, etc. But I’m also aware of a few software patents that, if I didn’t already know about them, I would not suspect were patented. For instance, One-click purchases, overscroll and simplex noise. I assume that there’s many more similarly-generic software patents that I’m not aware of. I can easily imagine unknowingly implementing one of these and then finding myself with a cease & desist or ..