In the last two weeks we've seen unusually high number of spam accounts being created and abused on the site. Despite sending and requiring email validations on new user accounts, there's some automation to bypass this process as well (or someone has a really really boring job to click on links in spam accounts).
While most of the domains used for this activity are relatively unknown and so far has had no legitimate account registrations, hotmail.com is an unfortunate exception to this.
For whatever reasons, spammers are able to use hotmail.com effectively to create fake accounts. And for that reason, website account registrations from hotmail.com have been temporarily disabled.
If you're already registered with a hotmail.com email account (as quite a few of you have), this will not have an impact on you.
If you do own an hotmail.com account and have no alternative accounts to use or feel it is important for you to register with this account, then feel free to send email to email@example.com and let us know.
If it looks like the spamming problem from hotmail accounts is reduced later on, we'll consider lifting the block.