Gregory Maxwell wrote:
I'll revise my position based on Aphaia's comment below: "I think that being at least the age of majority in their country of residence is important".
Checkusers are in a somewhat unique position to cause irreversible harm and cause legal problems for themselves and the foundation. As such they should be old enough to assume legal responsibility for their actions.
Just be glad that I'm not also suggesting that checkusers be insured. ;)
I disagree that the damage that somebody using checkuser privileges is necessarily irreversible and necessarily causes too many legal problems "for themselves and the foundation." There is obviously an extreme case or two where this may be the case, but on the whole I can't really seen where revealing the IP address of a user is necessarily going to be a major problem. At best, the worst damage that can happen is to document what computer an edit actually took place on. Only with 3rd party records would it even be remotely possible to tie this with a specific individual.
In addition, any user, including anonymous users, can trace the IP addresses of many of the contributors to Wikimedia projects.... that is the default log-in type. And accidental disclosure of IP addresses are almost inevitable for most users, especially if you accidentally make an anonymous IP edit because the cookie in your browser has expired (it has for me on a couple of occasions). For example (and I mention this because he also did one of these accidental disclosures and later noted this IP address explicitly) Richard Stallman of the Free Software Foundation fame is also [[w:User:Rmstallman]], and by only accessing Wikipedia by anonymous status (I wasn't even logged into my Wikipedia account), I can find out that at least one of the IP addresess he has used to edit Wikipedia was with 128.30.16.48
See http://en.wikipedia.org/w/index.php?title=Richard_Stallman&offset=200601...
Mr. Stallman in this case claims these IP edits as his own in a public manner, so in this case I don't think this is improper disclosure. But it is ilustrative of how people without checkuser privileges could still obtain this information.
I know that similar kinds of revelations of IP address can also be done with my own account. Or at least make a very strong circumstantial case where all you would have to ask the WMF or a "check user" would be something like "Could you confirm that address 10.44.44.22 is being used by User:Jimbo Wales?" Even if the WMF doesn't disclose this information, an investigator familiar with Wikimedia projects is very likely to be able to get this kind of information of a sufficient quantity that all of the protections of the check user privileges is essentially moot for users who have made a huge number of entries into Wikimedia projects.
I would further note that the discussions of trying to protect an anonymous user in China wrting something critical of the Chinese government are also moot, as that government can make a formal request to have that information revealed, and WMF policy is explicit to grant that kind of request.
I should note here that I'm not asking for checkuser privileges to be made available to all unregistered users, but I believe that the paranoia over how dangerous an individual could be even if they made a deliberate and conscious effort to disclose IP addresses for many users is way overstated. By giving this user scan ability to people who are otherwise considered trusted users on Wikimedia projects, for example admins and bureaucrats (I've long challenged that all bureaucrats should have this as a default ability), I fail to see what real damage is going to happen.
If a 10-year-old has been given bureaucrat privileges on a Wikimedia project, I would be very surprised. It may also present some interesting legal problems for the WMF in terms of liability for that user's actions, but I also believe that any such user who has achieved that level of trust in a particular project is going to have a level of maturity to keep from abusing the checkuser tool as well.
-- Robert Horning