Mysterious disabling of Gmail accounts.

Today I saw this blog somewhere whose link is put here which shows the comments of many users who mention of the banning of their Gmail accounts.It started an year ago but the comments were still flooding that the blog has locked comments now.It says google is banning accounts of many people with some mysterious reasons.some of them got their accounts back on writing to google in a period of time without any damage to their mails etc., but many did not.Many people have mentioned their usage of extensions of firefox etc which hacked gmail to increase their performance like GmailDrive,Grease monkey scripts etc., but I don't think this might be the reason.some people reasoned out that it may be a break in an invite chain and may be probably it is so.Gmail's beta state may be also a reason.So can we consider it to be a bug in Gmail?I have seen a post of a hacker in an Orkut community of his mentioning of banning of his all 13 accounts.Is the improper or the wrong usage of the customers is the reason for it?Or is it another Google's way of humour(I know it's far from reality)?Whatever it may be Google is mysterious