Just block phone numbers from questions by new users. Even if it's a legitimate question that belongs on the site, phone numbers are the sort of thing that would be redacted anyway.

Unless it's a 555 number (Warning! TVTropes link!). That should be fine, as it would be similar to using example.com.

Are we applying anti-spam filters to profile descriptions? That seems important.

I notice that that these all have a similar format, littered with non-ASCII characters, phone numbers, and long run-on sentences. We could block those.