I detected and reported the following bug last saturday, causing users to see vendors/signal providers MT4 investor password and account number!
The bug has just been fixed, but you may want to change your investor password to be safe. It could be that someone is copying your trades without your knowledge.
The bug appeared, if any user was following a vendors account on Myfxbook and this vendor account was been linked via Myfxbook AutoTrade. Then Myfxbook showed not only the users own accounts linked to Myfxbook AutoTrade, but also all the 3rd party accounts on the specific broker.