Robocalls and how they work

Have you ever gotten automated calls, where your phone rings and it's a recording on the other end?  Ever wonder how all of that works?  Brian Krebs looked into it:

Several times a week my cell phone receives the telephonic equivalent of spam: A robocall. On each occasion the call seems to come from a local number, but when I answer there is that telltale pause followed by an automated voice pitching some product or service. So when I heard from a reader who chose to hang on the line and see where one of these robocalls led him, I decided to dig deeper. This is the story of that investigation.

He dug into the business model, and who's shadier than whom.  And this is interesting, in a "red on red" targeting sense:

But he said those that end up buying leads from robocall marketers are often smaller mom-and-pop debt relief shops, and that these companies soon find themselves being sued by what Birnbaum called “frequent filers,” lawyers who make a living suing companies for violating laws against robocalls.

My heart bleeds for these smaller shops.  /sarc