to use the blind app, you'll have to use your intel email, that's the only way to register. be stupid enough to do this, and you are immediately hosed...
it's unbelievably really easy to get a subpoena for emails to be released, intel has done it before.
all what they need to do is to file a case vs. a john doe (google the term 'Doe Subpoena') and claim that they do not know the identity of the defendant, the court approves the subpoena before proceeding and owners of the app have to disclose it. if they do not comply, they are in contempt, at that point intel goes after whoever hosts data, provides domain names, etc. they are pretty much done at that point, so i guarantee you, they will comply and it's likely intel will get a full dump of all emails registered.
they can pull the same thing off on this site, yet here they have pretty much everyone using proxies or mobile access. when dealing with mobile access, verizon and att are pooling ip addresses, meaning that they have tens of thousands of users sharing the same address so it's pretty much impossible to figure out who posted what while on a mobile network.
i hope this helps...