<i>"The service checks to see if the hashed value exists and then lets you know if your udid is among the ones compromised. Only hashed values are stored in the service, not any of the raw udid values."</i><p>So all the site owner has to do is hash the udids to know who you are?
If your UDID tests negative, you still could be compromised. The original FBI file had 12 million. AntiSec released 1 million.<p>This linked testing site says 20 million, which is wrong, as far as I know.