I'm not sure about other states, but in GA there is a way you can get random telemarketers to stop calling.
Check out
www.ganocall.com
You have to pay $5 to be covered for 2 years but it's well worth it. The only catch some companies can still call you- they are:
-Businesses that have a previous or current relationship with the customer;
-Recognized charitable or religious organizations; or
-Political pollsters or candidates for public office.