[shawnee_]

The big picture here is that three customers' data was compromised -- customers in this context means entire platforms using Zendesk for support, not users. If the customers were, say, WePay, Box.net and OpenTable (random companies taken from their portfolio), this is potentially hundreds of thousands of users.

Also, it is a big deal because (as a former support person I know this), users often send in sensitive info with their support requests: SSNs, full credit card info with CVV data, date of birth (yes, sometimes all in the same message).

[unreal37]

The customers were Twitter, Tumblr and Pinterest. Wow, three of the biggest customers they have probably.

And two, the body of the emails was not exposed, only the subject line. People typically don't but their SSN in the subject line...

[ams6110]

It doesn't sound like the investigation is complete, so we really don't know what was exposed. If this was a sophisticated intrusion, the attackers may have covered the evidence that a lot more was taken, but just didn't quite get it all cleaned up.