That makes sense. I'm just surprised that this many people have apparently rolled their own signature algorithms with this flaw that running a bot to check for

That makes sense. I'm just surprised that this many people have apparently rolled their own signature algorithms with this flaw that running a bot to check for it is affordable. It's one of the most well-known mistakes to make in EC signature algorithms, and anyone researching how to implement these signatures should stumble upon high-profile cases such as the Sony private key leak, which should scare them enough to not trust that they can implement a reliable PRNG that won't generate the same nonce twice (with non-negligible probability). But I guess these bots check for a whole catalogue of mistakes, and this is a fairly cheap check to add if you are checking every transaction anyway.