I've spoken with quite a few people in chat that find it frustrating and sometimes impossible to catch the names of botters to report them. Here's the method I use. The more of us that can do this, the better ZOS can respond; and the more of us that flood them with reports on the same people, hopefully the more pressure it will create to permanently ban the IPs of bot users!
1. Identify botters as botting. This will usually be a group of sorcerors with two pets and sometimes an NPC trailing along. A prime example is in Silsailen, where there's almost never NOT someone botting. They will follow a set pattern, running from enemy to enemy and then pausing over them to pick up loot before they move on to the next.
2. Make sure your screencap hotkey is one you can use with your non-mousing hand. It can help to have it on the closer side of the keyboard to your primary hand rather than having to reach across.
3. Follow the botter group around, and when they stop to fight an enemy, pan across the group with your camera (mousing) and spam the screenshot button like a cameraman taking action shots of a model. You want to take many screencaps of the group as you mouse over the moving bodies. Do this several times. You can usually see if you've got the player names popping up between all the NPC names, they will be brief flashes.
4. With the game in windowed mode, open these screenshots one at a time in a program that can open images (I just do it in Firefox). When you find one that has the screen name of the botting player displayed, leave it open and look at the rest. There seem to usually be two cheaters at a time. This may be one person with two accounts, who knows, but look at all your screenshots and just delete the ones that show nothing but NPC names.
5. Open the Help menu in the game and pull up Support and then Report Player > Cheating. Put the player's account name in "player" and then supply their character name and that you see them botting at (location). I also include the names of any accompanying botters with each one to keep them identified as a group but also to make sure that none of them get lost in the system.
6. Report each botter name similarly.
I save the screenshots for a while, myself, and take the additional step of waiting to receive my email confirmation of the report and then replying to it with the screenshot of the botter in question. I don't know if that does any good but I took the durn pic so I'm gonna use it.
Hope this helps. I can say this: Whether it does any good right now as far as getting these people banned, I have no idea...but it feels good to just do SOMETHING, and to prove that their constant movement does nothing to protect them from identification.