am I supposed to go around to the webhost of every single person who downloads my script

They are supposed to spend five bucks for a basic hosting solution. C'mon, any highschool kid can afford shared hosting on a server with CGI support and an SQL database these days just by going to McDonald's once less a month. If they're such cheapskates that they won't even spend that little money, they're not likely to be worth your headaches either.