What makes it obvious that someone is hacking?

If they are flying around

 

when someone walks on water because they are literally jesus aka minecraft g0d

 

i dont think being me is hacking but thats a cute accusation buddy

 

It really would depend, if it were to be blatant cheats such as fly, bunny hop, or kill aura. It can also be hard to determine if someone is using a ghost client or knockback modifier. It may look like reach from different perspectives or it could be a client or when someones connection isn't the best.

 

usually kill aura is very noticeable.

 

for ghost clients, their cocky and childish attitude usually gives it away most of the time for me

 

When people get salty

 

Saltiness doesn't mean hacks -_-

 

To make it obvious someone is hacking if they are on KitPVP for example and there are two players beside the hacker. If they were using Kill Aura if both of the players are hitting him you will see a head spin if you look close enough and hard enough.