Regarding the #GMGN hack, I've read a lot of tweets and noticed several foreign users reporting hacks, but I haven't seen any Chinese users mentioning similar incidents. This is a bit unusual. After all, GMGN has a high percentage of Chinese users. If there were a large-scale theft, I'd expect quite a few people would come forward. If you're concerned about the risks, just report it and wait until GMGN clarifies the situation before adding more.