FYI - I use PhoneTray to block calls to a landline via a cable modem.  See phonetray dot com for details.  Also see nomorobo dot com which is a new (FREE!) service to that won an FCC contest to help stop unwanted calls.

I also file complaints on all of these calls at www.donotcall.gov and eventually some of these companies get fined (i.e. FCC announced a $7.5 millon fiine for Sprint this week for violations) although I know it's extremely difficult to catch spammers using spoofed numbers - which is where call blockers help out.

Caller ID showed "Muscle Loss."  Robocall - blocked.

A recorded message by a "doctor" about free treatment for anyone in my family with chronic back pain.  "Press 1 to speak to an agent" guarantees that I'll be blocking that number.