That was on my list of candidates as well! Those usually have a specific user agent making it clear what they are, they appear from a companies netblock (eg. Facebook, Microsoft) and cannot access authed pages (unless the key is in the url).
In this case these appeared to be all MitM'ed pages from a security device since the key wasn't in the url and it contained userids for a specific user.
In this case these appeared to be all MitM'ed pages from a security device since the key wasn't in the url and it contained userids for a specific user.