His solution is don't. Why would you? In fact, if you don't block the script that's running on one computer, the script operator won't need to run it on a botnet.

I don't know RMS's solution to spam or DDoS which are the real problems.

> Why would you?

Because controlling a large number of accounts can allow you to manipulate the algorithms on Web2.0 websites. For example, this one. If you don’t combat spammers the front page quickly gets filled up with garbage.