As far as I can tell, Assassin/Ghost will always piss someone off. Why? Because they keep you off the radar. It's that simple. I don't see why people still cry about it in MW3. Assassin is much nerfed from Ghost Pro in Black Ops and Cold Blooded Pro in MW2. Both perks were essentially Blind Eye and Assassin combined. People b*tched incessantly about Ghost Pro in Black Ops, however not so much in MW2 because Stopping Power was a much more prominently used perk from the same tier.
This game is a system of checks and balances. There is (supposed to be) a counter for mostly everything. Sitrep is designed to counter Dead Silence and enemy equipment, anti-air weapons are designed to counter most air support pointstreaks, and Blast Shield is designed to counter stupid sh*t like tubes and other explosives. Those are just a few examples I can think of off the top of my head. My point here is this: Assassin is designed to counter the prolific use of UAVs. I don't know how people think this perk is imbalanced. Does everybody feel they should be entitled to see everybody on the radar from a 3 pointstreak? A 4 pointstreak, particularly in MW3, is not tough to acquire by any means. In CoDs of past, you had to get kills to get your UAV. Now you have more options to get your killstreaks i.e. kill, take objectives, destroy enemy SAM turrets and/or IMS devices, shoot down enemy air support, etc. Not only that, but the support class allows you to maintain your pointstreak if you die, which is ironic because then it's not really a streak, but I digress. Because there are more ways to get points for your pointstreak and your killstreak doesn't really go away with the support class, getting a UAV is easier than ever. If it's easy as hell to get a UAV, then there's no doubt that UAVs will be used quite prolifically in the game. Therefore, such a powerful and easy to acquire asset deserves to have a counter.
Lots of people hated the Ghost perk in Black Ops with a passion. I always thought it was because Ghost Pro was quite the package: you could stay off the radar, have no red name or crosshair, be invisible to many killstreaks, and some other things that I don't quite remember. However, since everybody is still crying about Assassin in this game, which I see as a much watered down version of Ghost Pro from Black Ops because it was essentially split into 2 different perks in MW3, I'm assuming that as long as some people will be invisible to UAVs, there will invariably be a large amount of people that will cry about the perk that allows people to do so.
Some possible solutions? Many people suggest stupid things like Assassin should only make you invisible to UAVs for X amount of time. That's as stupid as saying Blast Shield should make you resistant to explosive damage for X amount of time after every spawn. My solution to this whole argument, though this would only apply to future CoD titles and, unfortunately never happen, would be to get rid of the damned radar entirely. Then there would be no need to use Assassin and there would be no radar for people to b*tch over because they can't see their targets on the radar. It's a win-win, in my opinion. This game would be so much better if there was no radar. I would just play hardcore all the time, but that sh*t's too damn slow for me to play on a regular basis. Oh how wonderful would be the CoD title that doesn't have a radar in core gamemodes.
Ghost Pro from Black Ops, though people still cried about it constantly, did have a counter: the SR 71 Blackbird. This, to those of you who don't remember much about Black Ops or have not played it, was basically a UAV on steroids. It lasted for 40 seconds, couldn't be shot down, showed you and your teammates the enemies' location and direction in real time, and Ghost/Ghost Pro was not immune to it. The Blackbird, however, was a bit of a difficult killstreak to acquire since it was an 8 killstreak (7 with Hardline). And this was back when there were no killstreaks that carried over through death, mind you. I think that an 8 killstreak was adequate for the Blackbird, since it was arguably the most effective killstreak in the game.
Infinity Ward really watered down that killstreak in this game. It shows the enemies' direction but doesn't show it in real time. It also can be easily shot down, does not show Assassin users on the radar, and, though it is a support pointstreak, is still quite a high pointstreak to acquire--12 pointstreak. The AUAV is nowhere near as effective as the Blackbird, which is a shame.
However, if you want an entirely failsafe way to solve the Assassin/any overpowered perks issued, then just get rid of perks entirely. Put every player on a relatively equal footing. The way I see it, perks are just an invitation to game breaking features and imbalance. So why should we keep them around?
I understand that much of CoD's success can be attributed to the perks system, but is it really making the game more fun?
I consider myself impartial in the whole argument over Assassin, but I will say that so long as there are UAVs, there should be a perk that allows you to remain hidden from them. However, there should also be things that can override perks that allow you to remain hidden from UAVs. This, however, is a setup for failure, since, for some reason, players feel they are entitled to knowing the location of every enemy for a mere 4 pointstreak. Therefore, if there is a UAV counter, there will be people b*tching about it. End of story.
P.S. To the people who say that it is blatantly obvious that most MW3 players use Assassin, quit pulling facts out of your a_ss. I'll stick with my Quickdraw, motherf*ckers.