Airbnb is an online service that helps home owners hook up with vacationers looking to rent apartments or houses. The idea is simple, while you're out of town on your own vacation - or even traveling for business - you can earn some extra green by renting your house.

As long as you rent your place to a decent, caring human being, it will all probably work out fine. A blogger who goes by EJ says she wasn't so lucky.

Three difficult days ago, I returned home from an exhausting week of business travel to an apartment that I no longer recognized. To an apartment that had been ransacked.

Now the company is taking some heat. Turns out Airbnb doesn't appear to carry insurance to pay for this kind of thing and won't reimburse EJ for damages.

Airbnb is one of many peer-to-peer rental start-ups popping up around San Francisco. And it's one of the latest little tech companies to convince VC investors its worth a billion dollars.