I'd say use the noticeably decked out for war look against him.
Just my guess is he's not using public transportation or walking in this, but who knows. If he is this idea can be easily adapted. Anyhow, have him get pulled over for a regular old DWT (Driving While Troll). If he's not wearing the armor at this time make sure the cop searches the vehicle under some pretense (not sure of the real laws in 2070s, could be real, could be tromped up). This will present a couple of likely scenarios:
1) He'll try to fight his way out.
Not the smartest move but totally possible. Course, the problem with LEOs aren't that each officer is super tough, it's that there's so many of them. Because this is a possibility I'd say be sure there are two officers, one approaching and another in the police vehicle. This makes it so that attacking and killing both in one move is harder and it's easier for one of the officers to call it in. Once called in, turn it into a major big deal. Cops chasing through the city for half the day, multiple hiding places, etc. Keep them on him until he gives up on the run, maybe even then some. This ought to give him and his armor a good old bit of notoriety. This whole scenario is a totally realistic response to attacking the police and reasonable in my opinion.
2) When in doubt, bribe your way out.
Much smarter, much more likely to work get him to his job. But will depend on just how much contraband he's got and how much he's willing to pay. The cop ought to look at this like a total payday. Either the player pays a bunch, or he brings in a troll with a ton of expensive contraband, and anyone with this much gear is likely a runner who's got a record somewhere and a rep... this is the arrest that could get him promoted to detective, so the bribe would have to be heafty to give that up. He can come out and even say all this even to our troll.
Best part is, if the player successfully bribes, you can have the cop show up again the next time, looking like he expects our troll. Why wouldn't he try to milk this?
3) He lets himself get brought in.
Very unlikely. Not so much because the consequences are the worst, but because players usually percieve it to be the worst and will do just anything to not get caught even when they weren't doing anything that serious.
Anyhow, if this happens then anything that there isn't the proper licensing for gets taken, he gets fines or worse depending on the item, and perhaps an item or two that he does have all the legal papers for "Gets lost in processing. So sorry. If you'd like to file a complaint please fill out form ....." yeah. The whole process should take him hours (Story time, not playtime. Who wants to roleplay that for 4 hours?).
And there are a ton of other things you can do too. You don't need to challenge him in a fight, sometimes you just need to remove or control him during a fight. I've had a sword wielding tank with Arcane Arrestor defeated by a mage casting levitate on him, and just holding him in place while the mage walked away dismissively. That sort of thing works too.
Anyhow, the goal being to annoy(character, not player) and show that being a walking tank just doesn't work so great in the real world, while still giving the player some freedom to choose how they react and what happens.
Course, this is only after you've talked to your player about being reasonable. That should be step one.