OK, this isn't another round of Harley bashing, or at least it's not intended to be. It just seems that it's usually Harley riders that are guilty of this, particularly when they ride in groups.
That being, they hold up traffic. Last month I was on Interstate 15 in San Bernardino County, California (I was riding from Las Vegas to San José that day). It's a 70 mph zone, but traffic easily flows, in the left lane, at 75 mph +, and I myself usually ride around at about 73-74. It was obvious as I was riding along that the car drivers were polite to me, since I'd get in the left lane ONLY to pass a slower car, semi-truck, or car towing a trailer (the latter 2 are limited to 55 mph in California), keeping with the traffic, then moving back into the right lane to let everyone else pass.
But I could see they were getting annoyed with the Harley riders; there were about 8 of them, and they were riding with those "ape hanger" bars that are about 1 1/2 feet higher than the seat. How they can ride like that is beyond me, but then they probably wonder how I can ride a sportbike, hunched over the gas tank!
Anyway, the Harley guys were holding up traffic, going a few mph slower than the rest of the traffic wanted to go, and not moving over to let others pass.
This isn't the first time. A couple years ago in California near Fresno on Highway 99 I had to get up to 100 mph to finally get around what must have been 15 or 20 Harleys, because they ride in a close group (try to imagine being able to get enough room to pass a 150-foot-long truck and you get the idea). Same thing one Sunday in Washington State on Highway 9 (and these jerks all had BC plates in this case).
Then there's the guys with unbaffled (straight) pipes, I suppose to make up for their micropenis condition....