There are two major acts that apply to unwanted text messages and canned spam. Unless you previously gave consent, or in the event of an emergency, text messages sent to a cellular phone generated via an autodialer are illegal. Pursuant to the Telephone Consumer Protection Act, these texts are illegal even if you did not put your number on the Do-Not-Call list.
The CAN-SPAM ACT (Controlling the Assault of Non-Solicited Pornography and Marketing) supplements the TCPA in that it prohibits a company from sending unsolicited texts or emails to a cellular phone if the substance is “commercial” in nature.
Pursuant to both the TCPA and the CAN-SPAM ACT, if you have given your consent, marketers are permitted to engage in the above described activity. “Consent” is a concept that has been litigated many times and is not as straight-forward as one might believe. It is recommended that if you believe you have been the victim of an unsolicited text or email message that you contact a TCPA attorney.