Well if I wasn't in the UK I'd probably use it to save carting the "recruiter" phone around with me as well. Of course, that would probably annoy recruiters but I think I can live with that (I don't mind them calling me in connection to a role I'd asked them about but 2 or 3 years on out of the blue?).

I am more sinned against than sinning, when it comes to respect for privacy.

Watch "The Wire."

Seriously though there are lots of licit uses:

-girl goes out to to pull. Gives her number freely knowing that it's only good for a few days.

- enter online competitions that might be spam. Advertise a job without getting onto a HR spam list

- Sell a used monkey online without fear of monkey spam

- Put up an MVP for a salsa lesson in Denmark. Get a local number using the app you already know about from the monkey business

- Set up sales meeting with your competitors (define licit..)

- Inform on your boss

- Call your uncle in Iran

I'm sure there are lots more. Who doesn't have some temporary/secondary email addresses?