but anyone can do that. you don't need an API to tell you if the address has a balance if you have the private key, you just check your own copy of the blockchain.... just like they are doing...

fgsfds

When you visit a page, they generate all the private keys on the page and check for balances. If you happen upon a key that actually has a balance, they will clean it out before you can.

I kind of doubt it, the browser makes a request to blockchain.info to check the balances. If they wanted to do what you are saying they'd make that request somewhere one the backend.

Well... yeah? It would make no sense to try and do that on the frontend.

well, very fun way to add randomness and entropy to checking. it plays on the maliciousness of everyone, by making them think the user has an edge.

they check balance by JS in blockchain, i no see in JS code they got info about result. If someone find btc wallet of Satoshi im sure what he got in donate (link exist :) ) enough for him ;) i personally like this idea. free lotto :)