Msg#: 4191113 posted 8:26 pm on Aug 23, 2010 (gmt 0)
Why You Can't Block Mark Zuckerberg on Facebook
"This error isn't specific to any one account. Itís generated when a person has been blocked a certain large number of times. In very rare instances, a viral campaign will develop instructing lots of people to all wrongly block the same person. The purpose of this system is to protect the experience for people targeted by these campaigns."