Convenience is often on the opposite end of the Security slider. Many people go whole hog on it.

Same with privacy, see Facebook.

Interesting point, because it suggests that an email address that was kept private and dedicated to Posterous posting could have prevented this attack. So, is this weak security on the part of Posterous, or excellent social engineering on the part of robinduckett? At the least, It's like he simply asked the target for a password; at the most, it's like he found the spare door key in the fake 7-Up can in the garden shed.

Note: Creating a "private" email address is beyond the capabilities of 75% of the people I know, who believe that email addresses are exclusively created and assigned by ISPs or employers. I doubt that Posterous will do anything to alienate this group, who appear to be an important target audience.