8007249093

I have received the same, including cards in the mail.

Same here.  Shows "ADT Security", but the number is not listed as an ADT number, and no message left.  If it really is ADT and they want to connect with someone, as a security company they should know to at least leave a message with a valid ADT callback number and the reason for the call.

Caller ID came through as ADT, LLC. After a very short wait a live voice came on stating that my ADT account required an update.  I informed the party that I have never had an ADT account, ever, and therefore did not require an update.  I stated that continued calls would be considered as harasment and would be pursued legally.  I also stated that they could not use my name or sembalence in any communications or promotions.  I asked to be removed from any call list and hung up the phone.  Funny part about all of this is that they knew my name...which I never admitted was mine.