Many of the annoyed recipients of these calls usually just don't answer when an unknown phone number shows up on caller ID, some answer and just slam down the phone when they realize they are getting yet another computer dialled recorded telemarketing call.
The problem with slamming the phone down on these callers is that the faster someone hangs up the faster the computer making these calls can make the next call to the next person to annoy. A better way to sock it to the operators of these shady operations is to leave the phone off the hook when getting one of these calls, firstly this slows down the rate of how many people they can call. Staying on the line for 30 seconds rather than hanging up after three seconds decreases the rate of calls made by 90 percent. Secondly staying on the line 61 seconds if their systems play their messages that long will double the cost to call you. The long distance calls that they make are billed by the minute even on cheap VOIP services. Once the call reaches one minute and one second the telemarketing company pays for a two minute call. Just by staying on the line it will take them longer to reach the big gullible fish to take the bait, and cost them more to cast their line in the water.