People I routinely play with believe bots are in BGs, but don't realize the extent. This post illustrates how to spot them, and how they have taken over BGs.
What I think most peopl don't realize, is that bots tend to play better than your average newbie. They're major flaw is they don't do strategic objectives. They pretty much just tunnel everything.
Great ways to spot bots:
1) "Soulwell test" is a great way to watch bots get their Lock cookies.
2) Shadowmeld in combat -- if you're in a group of bots, it causes an instant target switch to someone else, even if you only go stealth for a fraction of a second.
3) You can also spot them in Battle for Gilneas. They generally protect a flag in formation, until a base is assaulted. As soon as a base is assaulted they leave. You can usually flag cap behind them (and in plain sight) because they move with such clockwork precision.
4) EoTS -- you can watch the bot patrols move in a herd from base to base. They're easiest to spot at the very beginning, as they patrol on their side.
5) Bots also never sit in a CC. They always trinket if it is up. Which is kinda fun, cause you can set them up hard > Poly immediately followed by a Deep Freeze is fun.
Some classes are easier to spot than others.
Feral bots -- For whatever reason, these are the easiest to spot. They go hard. Don't target switch. Are like the Terminator. When they get low they always try to hardcast a Healing Touch. There is also a pause when they engage a new target. No idea why, but you can see it happen.
Boomkins/Mages stand at max range and chaincast. Pretty much don't move at all.
Now that honor upgrades gear (as does JP), I'm pretty sure botting is going to get worse (like that's even possible lol).