Botters are pretty easy to spot.

They stay in the base and blow all of their cooldowns/buffs. They'll do stuff, provided an enemy is within range. They just won't do it well.

One of them on our data center is called Comfort Luvbunny or something like that. I've only ever seen them on the other team, though, as it plays a healing class these days. It used to be a bard though.