Have the organization that he got the Armor from come after him. A nice explosion as he gets in his car. (just don't kill him. Hurt him bad and maybe destroy the armor)
On the last suggestion, once again, would you suggest destroying a mages foci if you felt a particular combat Mage was over powered in your game?
Y'know, this I really seriously don't get. This isn't the HERO System, where points gained are meant to be your points forever, (and even then, within certain strictures); this isn't ... y'know, I don't know of any other examples similar to that. Every other system I've gamed in, if there's an object or item, even one you spent weeks and months and years slaving over, spending XP/Karma on to create or bind to you, by the very
nature of the system and the game it can be destroyed. I don't care if you 'bought it with BP'; should your ammo be expected to never be expended because you bought
it with the money you bought with your build-points at the very beginning of the game?
No. Every toy your character might have, from the Eye of Vecna to the Arrow of Red Dragon Slaying to Iron Man power armor to a powerful magic focus that a mage spent karma to bond, is an item, toy, object, or gizmo that can be
taken away. Yes, a player has a right to feel picked on if s/he's the only one whose favorite toys keep getting wrecked - or, very possibly, the player should look at how they're playing, to expose those items to danger out of proportion. Yes, the GM should take the player aside if a particular something is proving to provide an overwhelming advantage; see link in my .sig to a statement about what game balance means in Shadowrun terms.
But would I suggest the destruction of an item that's turing the game into 'MyCharacterRun'? Hell, yes. I would suggest the destruction of any and
every piece of equipment the opposition could (and here's the key term)
reasonably get their hands on, if that's what told the story better. Hell, as I recall in one of the your-opponent-is-Blackwing adventures one of the PCs is meant to walk into their own home to find one of Blackwing's associates watching TV - and then at the end of a short 'leave it alone' speech, clicking a remote
that blows up that PC's vehicle. Never mind if the PC spent months building it themselves, modding it, spending tens or hundreds of thousands of nuyen on it;
the vehicle gets blown up. Period.
Toys, even cyberware, are there to make the character's job easier. Their removal can be, and the
possibility of their removal
should be, an integral part of the storytelling that the Game Master is engaged in with the players.
And before All4BigGuns wades in and says, 'I'm in control of my character!!' - yes, yes you are. Your choice of skills; your choice of what actions you attempt. Your choice of what your character says or tries to say; see the conversation about 'high CHA skill player, low CHA skill character' and vice-versa. But the player directs their character, and their character
only. It is the GM's responsibility and right to direct
all the rest of the game world, with certain exceptions as described by rules for combat, skill use, etc. It is
also the GM's responsibility to use that direction to tell a good, if not great, story; players whose characters serve as punching bags for the GM -- and here's the key part --
without commeasurate growth of their character do indeed deserve to throw things at the GM, vote the GM out, walk away from the table, etc. If, every time your house gets blown up and sixteen squads of pissed-off Ancients comes a-hunting for your character Bubba the Love Troll, you manage to survive, gain vengeance for your house, get a better one, and improve your reputation, well - you really don't have any real reason to bitch, do you?
Stuff exists to be used by the PC. If it's abused by the PC, then taking it away is a right, responsibility, and
requirement for the GM. Just because you got a lightsaber doesn't mean Vader can't slice your hand off and make you build a new one.