Board Thread:Support Requests - Getting Technical/@comment-25554800-20160729110528/@comment-24473195-20160729123505

Yes, that's the risk, that admins may use it for something other than just wiki things. In fact, if a malicious admin gets ahold of someone's account and adds their data that would result in a serious privacy issue.

Considering that they re-blacklisted the external image "whitelist", it is highly doubtful that this would be approved. I suspect Special:Contact is the best first step to avoid wasting time developing this, only to get it rejected.

Edit:

The Hash essentially obsfucates the code, it may be a random calendar for the wiki, or someone's private data. Staff has no way of knowing which it is, short of checking the data  for each hash. It seems likely that the drawbacks outweigh any benefits of this JS. In fact, there was an extension in Mediawiki.org that was removed due to security issues which seemed to provide this functionality.