According to the Federal Trade Commission Web pages on the Do Not Call registry, the federal law was changed so that Do Not Call registration becomes permanent. Also, telephone numbers aren't removed from the list, unless someone calls a specific toll-free number from the registered number itself.
Do numbers get removed from the list when telephone service is disconnected? Are telephone companies required to report actions disconnecting telephone numbers to the Do Not Call registry?
Does a land-line number becoming a ported number get it removed from the database? After all, telemarketers are required to avoid calling numbers known to be cell phone number, I'll guess by prefix and on the ported number database.
While I'm aware that the Do Not Call registry does not apply to charities, political organizations, and pollsters, are there any restrictions on unsolicited calls from those entities to known cell phone numbers? Lately I've been getting recorded political messages.