Pink Mohawk to be always just implied obvious visibility. In the case of Shadowrun, it means your character is easily-identified based on some credential(prominent horns, visible tattoos, a signature weapon, or even yes, a Pink Mohawk), whereas in D&D it could mean much the same thing but you don't hear about it. The reason for this is Shadowrun(read; running in the shadows) is a game where NOT being seen is the priority, considering you don't want most common people to witness the things you do. Whereas in D&D, it's the exact opposite(unless you're playing an espionage campaign), where you're big, badass hero-types who excel at kissing babies and slaying Orcs and looting the evil temple of treasure.
Anyways, as far as the issue at hand with sticky-fingered players, my philosophy, in Shadowrun and D&D, has always been quasi-realism. In that, to move the story forward, sometimes you let the players get away with stuff, but generally there are ALWAYS consequences. Everything people mentioned above is good depending on the situation. They might get garbage data, they might get a tagged item that a Corp can trace them with, they can only carry so much if they're stealing physical gear.
Personally, my favourite is the Johnson politely suggesting before a run that they ONLY go after their target item on a run and leave the rest alone. Say it's an illegal weapons testing center, and they're paid to make off with a prototype shotgun or something. They can go in, get the gun, get out unseen, and get paid. However, they'll have ample opportunity to filch a bunch of other, potentially-lucrative weapons and gear from the place. Now, street-level smarts would suggest to leave them alone, but the temptation may be too much. So they take a handful of these high-tech guns. They even think they're clever by scanning them for RFID tags and using a Tag Eraser on them. But here's where it gets fun.
These weapons were prototypes not just because they're a new model of small-arm, but because the company is testing a new type of RFID tag that lays dormant and supposedly undetectable until the trigger is activated, in this case if they pass through silent perimeter scanners at the edge of the facility. SO even if they scan for RFIDs before they leave, it does no good. The reason the Mr Johnson wanted that one specific gun is that it's the newest prototype top be shipped there, and hasn't had one of these dormant tags installed yet.
If they hock the guns at a pawn shop or Bob's Bullets or whatever, they see in the news or through a witness or something later on that a huge LoneStar/Knight Errant raid goes down on all these places. Basically the corp paid a LOT of money to get these back. Johnson is pissed, because he gave specific instructions to avoid this kind of clusterfuck, and the PCs deliberately went off-mission to try and get some extra Nuyen on the side. He then tells them in no uncertain terms that they get 60% of the agreed take, as the other 40% now goes to his expenses for having town leave town for a while because of the heat. As a consolation prize, due to their abject lack of professionalism, Mr Johnson is now deleting them from his contact list, as well as his network of fixers, contacts, and anyone else he knows. Meaning their notoriety takes a spike as well.
That's not to say that they can't stay in Seattle/other setting and find work elsewhere, just that they will likely find work a bit slim picking the next while, until they re-establish themselves through other people as a reliable, professional crew again.
Point of all this is it's not a final death knell for the team, and yes, the run was designed to test how well they take directions from the person who's goddamn paying their bills, so it was set up with a moderate chance for them to screw it up. However, it's designed as a wakeup call, which nearly every runner has had at some point in their career. If you agree to do X to get paid by Mr J, you go and do X, and that's it. That's where they get respect, and more people hire them for jobs. If they do X but also do Y, take a little J and T on the side, and maybe plug M full of holes, why in the Seven-Hells would ANYONE want to work with that team again?