Maybe SWAT can use this to validate that it's actually the right house when serving a no-knock warrant. I'm cynical enough to feel like there's no way this is good for any of their targets, though.

Edit: Kolpa makes a really good point! This seems like a really good counter to SWATting, where the claim is that someone is holding hostages or something -- this could pretty effectively demonstrate that to be false if they see one person in an apartment sitting at a computer.