I'm actually working on a mod right now that places several Thalmor Hunters in the world, and they camp along the roads waiting for Thalmor patrols. When they appear, my people slaughter them and take their heads.
Still got a few bugs to work out, like getting the correct textures on the head once it's removed, as well as whatever they were wearing when it was cut off - hair, helmet, hood. That part of it is apparently going to need a functioning NIF plugin for either Max 2015 or the latest version of Blender (functional = one where I don't have to change or strip info from the NIF to even import it), but it doesn't look like that's going to happen this year. Maybe when Failout 4 hits it'll be a concern.
The most interesting part about the mod IMO is that the game re-routes Thalmor patrols to try and avoid my Hunters, or it spawns more Imperial patrols with Prisoners. I've seen Thalmor cutting cross-country from Whiterun to Rorikstead since I started making the mod, as well as a double patrol (6 Thalmor and 2 Prisoners) in areas where I hadn't yet placed Hunters.
I've also got a basement where 15 dead Thalmor hang by their necks from the rafters.
Right now all you can do is travel to their roadside camps and watch them do their thing is a patrol does come along.
The back-story is that these are the children and younger siblings of the Blades whom the Thalmor hunted down (including the 100 agents whom they beheaded in Valenwood and the Summerset Isles, and whose heads they dumped at the Emperor's feet). So now, 30 years later, those kids are all grown up, wearing their parent's armor, and are collecting a thousand Thalmor heads, including Elenwyn and the other named Thalmor.
Ultimately it's going to be a viewable quest where you'll get to see them torture, maim, and behead Thalmor agents. I need to work up a set of animations where they get their hands chopped off so they can't cast spells, are dragged around Skyrim on a rope with their eyes and tongues cut out, and finally led to the Embassy, where Elenwyn is dragged out and butchered like a pig, then shipped off in pieces to Thalmor HQ.
There'll be dialog between the Hunters and Tullius, where Tullius will cry about leaving the war against the Dominion to the Empire, and he will basically be told to STFU unless he wants his head removed as well (immediately followed by the wanton slaughter of his bodyguards to show they're not joking, and Tullius will walk away with a permanent limp).
There'll also be dialog with Delphine, where she will try to recruit them into the Blades, but they're out for vengeance rather than sitting in Sky Haven Temple and hearing about "the old days" and dragons. They're waging open war on the Thalmor, not crying about Paarthurnax or the Greybeards.
But yeah, soon as I can get my hands on that NIF plugin, everything else will fall into place.