Target for attribution links differs between maps

In some cases (for instance Bing maps terms of use) the attribution link is opened in a new tab or window (target=_blank) while in other cases (like OSM) the links open in the same window.

I think they should all open in a new window (or all NOT in a new window if that is what is preferred). At least it should be the same for every map. Maybe the best option would be to make it a choice whether you want the attribution links to open in a new window.