There's been this one scam that's been using Microsoft's identity to get information. The person on the other end claims that your computer sent them a message that means it has a virus and wants you to turn your computer on for them to make the fix (in addition to enabling them to do it).
Years ago I fell for this scam out of India and nearly had a heart attack. I learned everything I could about tech so I never felt the need to use such a service. The thing that makes it creepy is that it has happened with every computer that's been bought at Best Buy.
The phone company won't block the number unless a add on is bought and when asked the price of the add on the person got snotty and said "it's not my job to know that - it's the business department's job."
So...no blocked number :( *shakes fist at Centurylink* curse you.