comcast will not let me block this number; it says that the number does not exist and therefore cannot be blocked. I did try to dial it and indeed it is not a working number. BUT I KEEP GETTING CALLS WITH THIS ON CALLER ID! It is obviously masking the real source deliberately. Wonder what would happen if you actually agreed to let them clean your ducts!
Caller ID: MARYLAND
FYI: 555 exchange is used primarily for legitimate information numbers (ex: 301-555-1212 is for information lookup a $1.50 charge) 555 oftentimes considered a "dummy" exchange-movies and tv shows use them for fictitious telephone numbers. What we have here is a "spoofed" number.
Telemarketing call for furnace and air duct cleaning service