On Wed, Oct 16, 2013 at 1:59 PM, Jaime Anstee janstee@wikimedia.org wrote:
It was actually legal that identified it as a problem, but I think that is being handled by good faith in people not releasing/pubishing cohort membership of any individual level data with identifiers. Many program leaders will be able to match different data points by user name also whereas most do not know what to do with the IDs (which made the IDs a bit more private) - Jaime.
If any person has access to user ids you should assume they also have access to usernames. Both are public information. Assuming numeric ids are more private is security through obscurity.