> Call your cell phone provider and put a “do not port under any circumstances” hold on your phone number.

Jokes on them, my number is ported to google voice, and they don't have customer service...

i just got off a DM with TMo support. they officially don't have a way for you to block this. Sucks considering they are the best of the worst. Every Tmo customer is in danger of having their identity stolen.

I haven't heard of a 'do not port' instruction, but you can call T-Mobile and add an additional password that will be required before customer service will service your account.

Unfortunately numbers can usually be ported out with just name, account number and zip code. There is a lot of port fraud happening.

I ported my wife's number last week from Verizon to Sprint, a 4 digit PIN was required in addition to the account number and phone number.