Most? That is a pretty serious statement, and I really doubt you can back it up. I don't have statistics on this and don't know where to look for them, but I would guess that the numbers of HN'ers that have had an account closed by a BigCo is actually much less than 1%, never mind more than 50%.
Am I grossly underestimating here? Keep in mind that these stories tend to be very popular, so there could definitely be a lot more of these stories around than is statistically correct.
P.s. As for one of cletus' point above, I've also noticed a few of these kinds of points eventually bring out more details which tend not to confirm the events, as told in the original posts. Nothing specific to this case of course, I've just caught myself a few times thinking "hmmm, looks like it wasn't such a crystal-clear case of the company being wrong".