Hi,
Setting the user under-which a web service could be called,, to anonymous, while setting the internal impersonation to an elevated user, could technically work nicely, but this way any user could call this web service (unless e.g. no access to web server itself).
Alternatively, setting the user, under-which web service could be called by, to group of specific users, may complicate implementation of web service, when elevated access rights required for the web service code to run, requiring some smart solution. This is probably not a "rare" case, yet didn't find a ready solution off-hand and simple search, hence would appreciate a referral to some good article with solution and example.
Thank u