Z:gnu-www-ja-danger-of-software-patents--2e7a0b-Well, you can't find all the p/en

Well, you can't find all the patents by searching, but you can find a lot of them. And then you've got to figure out what they mean, which is hard, because patents are written in tortuous legal language which is very hard to understand the real meaning of. So you're going to have to spend a lot of time talking with an expensive lawyer explaining what you want to do in order to find out from the lawyer whether you're allowed to do it.