This seems to be a general problem affecting all the places where group names are returned via Web Services.

The group name is not properly filtered hence is not possible to retrieve just the content filtered (multi-lang not working is the most typical case)

There is an additional problem with the WebServices exported via AJAX, is not possible to indicate which language to use/force (as it can be done via Web Services) so it won't be possible to select the language of preference for the filtered text.