Phone spam.

It interrupts employees' train of thought, but many people can't simply not answer their phones: a salesman who doesn't answer incoming phone calls isn't very effective at their job. Gone are the days where you could tell by the caller ID.

It's fun to think about a crew of mercenaries who travel to whatever corner of this planet, find the autodialer equipment, and take a small brick of C-3 to both the equipment and the owner, but would just settle for finding a way to stop it transparently.