What not to do
I've been getting SMSes for the past few days that look like this: Mike Wills (Minneapolis / St. Paul, MN) has requested to add you as a friend. Reply 'a' to add, or 'info' to get profile. That's all. I have no idea what service is sending them; they each come from a different generated number like "32665301". I'm certainly not going to reply to them.
Someone designed and implemented that. Did they never test it?