[Bish0pQ]

yes as cell phones. so I send the message as an anonym

That's going to be rather hard. I don't think this would be very easy, not saying impossible but hard. If the restaurant (in this example) would have somekind of login page you could try to do dns poisoning thus referring them to a page you made yourself where you ask for the phone number and afterwards rederict them to the main login page.