"Goodbye" phone call

[Clam]

Weird phone call I've gotten a few times lately. It's a recorded message:

...
...
...
...
...
...
...
...
...
...
Goodbye.

[Simon]

There are thieves hiding in the bushes, testing whether you're at home or not.

When they call you on 4 consecutive weeks at the same day/time each week, and you never answer, they will conclude that it's safe to burglarize in the 5th week.

[Clam]

Initial googling suggests that this is quite the mystery. The best theory I've found so far is this: Telemarketers have a device that dials people automatically, but don't have an actual person available to talk to you when they dial. It would seem more sensible (and much less creepy) to just hang up right away rather than play this, even given it's a friendly sort of voice.

Or it could just be hacker kids playing pranks. I'm open to any and all crackpot theories

[mobius]

I've been getting these calls where a machine is in the middle of a conversation:

"-eply now for a limited time offer! thank you and have a nice day!"