Only AA and AAA corps are given extra-territoriallity (sp?) This means that if you are banking with Ares (for example), then you gave them some sort of acurate info (be it DNA, fingerprints, voiceprint, occular pattern, what have you). Does this mean you do a run against Ares (any subsidiary), you will be caught immediately?
I don't think so somehow.
First of all, a good runner would wear little things such as gloves, contacts, disguises, etc. etc. In fact, would wearing, for example, a decent full body armored bodysuit (the messenger 6/6 armor) w/ helmet would pretty much protect you from the camera's and leaving little bits and pieces of yourself (unless you get shot and bleed out.) For those instances you have to rely on sterelize spells or, there is always a small bag of bleach/gasoline/acid that you can pour on the blood spill (cheap) or even more exotic cocktails.
Secondly, remember, its "each man for himself" in most corps. If the bank manager thinks he can shaft a rival (perhaps for future promotions, even in a different subsidiary) and he thinks he can get away with it ... he will.
Thirdly, why would a semi-intelligent runner go around broadcasting the SIN he uses with that bank, on a run against a corp owned by the same mega as that bank? I would use a high rated fake SIN when banking, and an expendable SIN when running (probably with multiple backups along as well.)