In Japan (at least in the past), the Christian cross has been popular as a necklace. People there, particularly girls, wear it for fashion but they're not Christians at all. It's the same as hippies wearing Buddhist symbols yet not knowing or adhering to a single thing in Buddhist doctrine.
A WG wearing a cross doesn't bother me. It's just a piece of jewellery and does little more than make a statement of how stupid religions are. Most, if not all people who claim to be Christians are hypocrites in some form or other.