How do the GMs detect hackers?

I dont think so i always farm before whole night on xenia continent and i dont get detected i got a 4 level 65 characters in just 4 days and unlock all jobs and i one week i got all jobs at level 65 except for ronan and ryan all 4th jobs

for gcph never use the hack for leveling that is obvious. i see lvl 60's but their shield is still a skull lol. its pretty obvious they are hacking
so i suggest you do pvp first .

just dont use mp hack..because if you happened to play with me, even if you are my team mate, i'll be sure to record the vid...
btw: i reported 150+ users of mp hacks (and they got banned)..meaning, i lost 150x because of those f*cking mp hackers..^_^

@TS' question

GM's may enter your room unknowingly .. but you can detect a GM in a room if you saw a room that has 7 players even the capacity of rooms is only 6 ..
Unfortunately, if it happens that u'r using a hack in dungeons and a GM had entered your room(since GM can enter even though you cannot see a character entered your room) then your account is already doomed..

dont over use low levels to have a quest on high leveled maps.. specially the 3rd map

Don't use extreme low levels on extreme high dungeons (ie Lv 0 Mari + 2x + Perfect Star Hack + SD hack + Thanatos Champion = Mari Lv 8-10).
Causes heavy suspicion.

why when im running sir makim's hack, suddenly i saw ''recording'' right side bottom.. issit a gm that is recording it?
btw i quit the map right away~

dont abuse hacks in PVP.. that the first.. u are getting advantage in tehm specially to MP hacks.. Use it only in dungeon.. Dont over use it.. Even sometimes we smust be fair.. :)

me to i got banned for using mp hack =(

Humm....

I think MP hack might actually be possible in PvP or PvE, SO LONG as you don't abuse it like a moron (especially on Arme, Mari, Counter Armor, Skill Spam, etc).