When you click the 'share' button beneath a post on MathOverflow, a box pops up containing a short URL for the post, e.g. of the form


Unless you have been reading the (contentious, at times) thread "Privacy of software-generated links to questions and answers", you may not realize that this URL identifies you. In particular, the trailing '3' in the example above is my user number, and my identity can be found by entering the URL https://mathoverflow.net/users/3.

Stack Exchange staff: Can we please remove the trailing user number from the URL generated in the 'share' box, on MathOverflow?

Notably the 'share' link is the most accessible way to obtain a URL direct to an answer (as opposed to a question). The 'cite' link also provides a URL, with no personally identifying information, but it is slightly less obvious to extract.

There is an existing long discussion of this issue, sadly at times generating more heat than light, at the above mentioned thread. I will quickly recap the pros and cons of the trailing user identifier here.

Pro: the "announcer" badge rewards people who bring attention to StackExchange hosted threads, by posting these links in other fora. The trailing user id is used to track the number of visits due to a particular user.


  1. At least some of our users are discomfited by this personally identifying data being surreptitiously embedded in a URL.

  2. It is conceivable, although there is no known case of this occurring, that this personally identifying information could break the expected anonymity of mathematical refereeing. It is certainly very plausible that a referee will at some point (and likely this has already happened many times) want to tell authors about a post on MathOverflow relevant to the refereed paper. If the referee uses the URL generated from the 'share' link, they will accidentally reveal their identity. It is unreasonable to expect that users of this URL are aware that it may reveal their identity.

Discussion: Personally, I couldn't care less about the Announcer badge (and I think the other moderators, and much of the community, agree). I am not comfortable with MathOverflow revealing personal information in an unusual way that discomfits some of our users. I am quite concerned about the potential (admittedly hypothetical) impact on a referee.

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    $\begingroup$ Point 2. of the cons seems to be a very serious problem for any academic community. I am quite sure that implementing this feature request just for MO (not for the whole SE network!) is easy enough for the SE system developers to do. MO is not just another 08-15 site in the SE network but has a special agreement with the company. If the MO community feels indeed that this user-identifying mechanism is a problem, SE should therefore take this feature request very serious and timely and positively respond to it as needed. $\endgroup$
    – Dilaton
    Mar 10, 2016 at 9:25
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    $\begingroup$ Why do you address "Stack Exchange Staff" here in meta.mathoverflow ? I agree that stackexchange as a whole is where this should be discussed. $\endgroup$ Mar 10, 2016 at 15:02
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    $\begingroup$ I am astonished you do you not at least include the result of the poll that was part of the discussion. A very clear majority of users is in favor of changes yet not removing the personalized link. (36) The option you propose (removing it) with 10 is even less popular than not doing anything at all (16). While I believe that such things should not simply be decided by vote as the situation is not symmetric, I believe there are solutions that address the concerns while preserving the personalized link and I do see no justification to simply ignore the expressed majority opinion. $\endgroup$
    – user9072
    Mar 10, 2016 at 19:18
  • $\begingroup$ @Dilaton There was a poll and this proposal (removing personalize link) was a distant third in the poll (see comment above for details). The favored solution of this community in its majority is one of compromise and more transperancy yet not outright removal. $\endgroup$
    – user9072
    Mar 10, 2016 at 19:25
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    $\begingroup$ @GeraldEdgar, because this is an appropriate mechanism for making requests for changes to the software. $\endgroup$ Mar 10, 2016 at 22:53
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    $\begingroup$ @quid, I didn't repeat the poll votes tallies because I considered the poll rather overcomplicated and confusing, and unlikely to lead to useful concrete action. Interested parties may review that thread. As far as I can tell, no one has actually expressed any reason for objecting to removing the user id, and all the other proposed solutions are complicated and unlikely to be implemented. $\endgroup$ Mar 10, 2016 at 22:57
  • $\begingroup$ To be clear, do you propose this for all sites or only MO? If only MO, the mere fact that then MO will differ is a reason against it. This could actually bite somebody. Namely a user that is mainly an MO user and then wrongly assumes the behavior of math.se will be the same and then say link to a math.se answer in their referee report (to stay in that scenario). I really hope SE will not give up unifomity here. I doubt they will scrap the id throughout. By contrast, making it transparent seems conceivable even throughout. $\endgroup$
    – user9072
    Mar 10, 2016 at 23:15
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    $\begingroup$ I was proposing this only for MathOverflow (I think this is already clearly stated above). I'm not concerned about any of the other Stack Exchange sites, or the impact of changes here on them. $\endgroup$ Mar 10, 2016 at 23:21
  • $\begingroup$ I specifically talked about the impact on MO user when they occasionally use other sites. I am extremely disappointed how this is approached. $\endgroup$
    – user9072
    Mar 10, 2016 at 23:28
  • $\begingroup$ One more point then I leave this discussion for the time being: "Personally, I couldn't care less about the Announcer badge (and I think the other moderators, and much of the community, agree)." There is no need for speculation as this was discussed The situation is a lot less clear than you describe it (though personally I expressed my opinion rather against those badges there). $\endgroup$
    – user9072
    Mar 10, 2016 at 23:49

1 Answer 1


Apologies in advance if this has already been requested: an anonymous share button which provides the desired functionality of giving the URL without the appended user ID.

However, I think an even better solution is a raised level of awareness, both on the developer and on the community sides. Relabeling the share button as "share with id", along with a message in the popup menu mentioning that (an intermediate copy of) the URL string can be further edited, should be enough for most people on academic forums to handle.

Gerhard "Call It An Intelligence Test?" Paseman, 2016.03.10.

  • $\begingroup$ This matches roughly the clear winner of the poll we had months ago. Personally, I thought the "cite" button is sufficient, but one certainly could go a step further if needed. $\endgroup$
    – user9072
    Mar 10, 2016 at 19:28
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    $\begingroup$ I'm not sure why we want to raise levels of awareness about a problem that could easily be made to simply go away. "Raising levels of awareness" is a rather difficult process, to put it mildly. People don't read stuff, and more importantly, they shouldn't be made to read stuff unnecessarily. $\endgroup$ Mar 10, 2016 at 23:00

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