Answer: NASA

In 1979, NASA’s decommissioned Skylab space station re-entered the Earth’s atmosphere and came crashing down in a sparsely populated region of Australia. Not so sparsely populated as to go unnoticed, however. Skylab’s trajectory brought it uncomfortably close to Esperance, Australia where its pieces damaged several buildings and, allegedly, killed a cow.

The city of Esperance sent NASA a $400 (USD) bill for the clean up, but never received word back from the space agency. Thirty years passed, and in 2009, the city (mostly in jest and to drum up a little publicity) put up a handful of billboards reminding NASA of the outstanding bill. A radio DJ in California, Scott Barley, asked his listeners to chip in a few bucks so they could finally settle the outstanding debt with Esperance. The money flowed in and Barley flew to Australia to deliver the check in person. In keeping with the whole tongue-in-cheek light-heartedness of the affair, the city of Esperance had the billboards stamped with a giant “Paid in Full” mark as if they’d been cleared by a giant accounting clerk.