Red Bull absolutely walked away with a win at Montreal, but anyone watching the exit of the hairpin would see something was up with the way the RB9 exited the corner. Have they figured out how to use illegal traction control?

Axis of Oversteer certainly thinks so. Traction control has been banned in F1 several times in the past, most recently in 2008 when every team started to use a standardized ECU. How could RB have traction control, when the stability programming is banned? Axis believes it could be in the engine mapping.

Traction control as a specific component is banned but its function is now duplicated by all, with different degrees of success, via engine maps that manipulate torque curves and use partial firing of cylinders to achieve the a similar result. Mapping is one of the black arts of modern racing and one essentially impossible to police.
Even with the insane tech of today's F1 the old maxims still apply: " if you 'ain't cheating, you ain't trying" and " it's only cheating if you get caught".

Axis points out that if you can see it on TV, every other team in F1 has known about it for a while. And probably complained to the FIA. And tried to duplicate the system in the meantime.

Honestly, I wouldn't even be mad at Red Bull if they are making a huge, illegal leap of performance over the other teams. I'd just be impressed.

UPDATE: Many of you pointed out that the juddered tire marks from Mark Webber leaving the harpin are likely not evidence of traction control in action. As F1 tech commentator ScarbsF1 pointed out "It would be a pretty poor TC if it created a stutter effect like that!" He goes on to explain that what we're seeing here is driveline oscillations.

@Formula1extra @SomersF1 Nope, its just drivetrain oscillation causing a momentary change in toque at the wheels

— Craig Scarborough (@ScarbsF1) June 18, 2013

@thejudge13 @Formula1extra I guess its possible if the system isn't damped properly then a front to rear rocking motion could be set up

— Craig Scarborough (@ScarbsF1) June 18, 2013

@thejudge13 @Formula1extra these fluctuations would alter the load at the contact patch, leading a dotted tyre trail.

— Craig Scarborough (@ScarbsF1) June 18, 2013

@jayracing @SomersF1 @Formula1extra I get it in my FWD roadcar when I get too much slip, you get a real thump from the vertical oscillations

— Craig Scarborough (@ScarbsF1) June 18, 2013

Moreover, F1 commentator Steve Matchett states that he spoke to four teams and none of them had a single complaint or suspicion about Red Bull or TC.

Bottom line, however, I haven't heard one complaint from anyone within the four teams I've talked with that Red Bull are using TC. Not one.

— Steve Matchett (@MrSteveMatchett) June 19, 2013

@willbuxton Media generated grassy knoll stuff, Will. When engineers from 4 teams independently tell me the same reason, I'll go with that.

— Steve Matchett (@MrSteveMatchett) June 19, 2013