This type of scam is big business in rural Iowa (and I'm sure other areas).
I used to work in rural northwest Iowa. We had a "programmer" (to use it loosely) quit to work for a company who's sole purpose was to abuse this system.
They ran a "phone company" in a small town and then connected a big asterisk box at their local exchange to accept free conference calls. They then installed smaller asterisk boxes in other businesses that were a long-distance call away with for the sole purpose of keeping the lines coming into their conference box 95% full 24x7 with bogus calls from 5-45 minutes long.
I used to work in rural northwest Iowa. We had a "programmer" (to use it loosely) quit to work for a company who's sole purpose was to abuse this system.
They ran a "phone company" in a small town and then connected a big asterisk box at their local exchange to accept free conference calls. They then installed smaller asterisk boxes in other businesses that were a long-distance call away with for the sole purpose of keeping the lines coming into their conference box 95% full 24x7 with bogus calls from 5-45 minutes long.