I think you misunderstood (which I figure is a fault on my part). The product on the frontpage is what has been curated today. But this made me think of something else; I should probably add product descriptions.

Lockitron[1] is not what he built, but is just the latest product to have been curated.

Lockitron is a YC-company and, to answer your question, this is from the Lockitron FAQ:

Unlike lost keys which anyone can use to unlock your door, in the event you lose your phone you can disable its access by resetting your account password. Never worry about changing your locks again.

[1] - http://lockitron.com/