Chats,
According to http://www.ftc.gov/donotcall and the Federal Trade Commission, this is not the case. It says on their page that you can register your cell phones, but it is against the law for automated telemarketers to call your cells. Here's what it says:

Cell Phones
You may place your personal cell phone number on the National Do Not Call Registry. The registry has accepted cell phone numbers since it opened for registrations in June 2003. There is no deadline to register a home or cell phone number on the Registry.

You may have received an email telling you that your cell phone is about to be assaulted by telemarketing calls as a result of a new cell phone number database; however, that is not the case. Federal Communications Commission regulations prohibit telemarketers from using automated dialers to call cell phone numbers.