Originally Posted by
Bonehead
Note that the poster said "usually". That's why I left his comment as it was...he was correct. I have certainly seen flights where one or two bulkhead seats were selectable, but in my experience, it has been more common to see all bulkhead seats blocked.
I would hazard that they were selected already, not blocked. If there was a situation where I couldn't select them it was because they were already occupied, not because they were blocked.