How can u tell when some1 in aqworlds is online but he iosint in your friend lsit but in another server?

beacuse my aqworlds acc was hacked and i keep puttin my pword and duh hackr i ko him and he said he wouldnt change my pword but my lil bro told him my pword so yea i need 2 kno when he is online and wat server he is on cuz he isint in my friend list