Is this outrageous behavior? Not really. It's how I drive, and so does virtually everybody else, though for some reason when cyclists slow down, make sure it's clear and then proceed, it raises the ire of motorists.
There's a good reason for this behavior, and it has to do with conserving momentum. It's a somewhat bigger deal for cyclists, who have tiny reserves of power and hate to squander it in coming to a complete, track-stand or foot-down stop, then have to accelerate from zero, over and over again (read about this in a couple of articles by a prof at Berkeley here in English and here if you want to check the math). It's a factor for autos, as well, and people who swear that they stop will slow down to 6mph or so (I've paced many motorvehicles through stop signs to see how slow they were) and then go.
Well, one guy stops. In Slate magazine one of their columnists made a comment about this yesterday, in relation only to cars and having nothing to do directly with bicycles.
Possibly bad idea of the day: I got a ticket a couple of years ago for failing to come to a complete stop at a stop sign. I was so guilty. Ever since then--and after I was admonished by a cop I met at a party--I've tried to come to a total, 100% stop, with the weight of the car falling back on its haunches, before stepping on the accelerator to get moving again. When I do this I can hear and actually feel the engine sucking in vast quantities of precious refined petroleum to overcome the inertia of 3400 pounds of metal at a dead rest. Which leads to the thought: Wouldn't we save a lot of gasoline quickly and cheaply if we replaced most of our "STOP" signs with "YIELD" signs? I'm sure there is a safety argument against this, but I'd like to hear it, along with up-to-date comparisons with countries that rely on "yield" more than "stop." ... N.B.: a) You could still require that everyone slow down to under, say, 10 miles per hour. It's the first 10 miles per hour starting back up that seem so gratuitously wasteful. (Maybe "YIELD" is the wrong sign. Maybe it should say "SLOW to 10.") b) Traditionalist drivers--e.g. geezers--could still come to a complete stop and retain the right of way. c) Policemen could still raise revenue for their employers by giving lots of tickets--they would just be tickets for "failure to slow" or "failure to yield." ... 3:51 P.M. (here's the link).
People already do this. Interesting that he picked 10mph when people often do 6 or so already. Maybe a car going from 30 to 6 looks like a stop but a bike going from 14 to 8 doesn't. (I've written about this before, in July 2005: you can read my previous masterpiece here if you missed it the first time around).
Separately, there's a flap on in Toronto where a motorist got pissed off at a cyclist (ironically, for stopping for a yellow light), got out of his car, and punched the cyclist, breaking out a tooth. Nothing out of the ordinary, except that some school kids were filming it. It turns out the motorist was an off-duty cop. One wonders at the message being sent: "You cyclists piss me off because you never stop at stop signs or red lights, but by God, if you do stop at one in front of me, I'm going to punch you out"? You can see the video over at Martino's Bike Lane Diary and the links flowing out from there. Reading through the comments can be both entertaining and annoying--some note that the teacher was hot, others say they have conceal and carry laws in Florida and that they'd just shoot the cyclist in the face. That seems like a twisted fantasy; if you want to kill a cyclist, all you have to do is run them down and you're likely to get away with it. Just make sure no school kids are filming you at the time.