> When your IP is found to have been part of a botnet, I think ISPs should just limit you to like 20Mbps for at least a year, so you think twice about buying that 10$ wifi baby monitor next time.

You're talking as if people can't just get another account or change ISPs.

Also, it seems you're mainly interested in gratuitously punish people who are powerless about issues instead of thinking about very basic approaches such as rate-limiting policies.