It depends on your definition of "threaten", but the short answer is yes. I live in a mountainous area that's a destination for road bikers and mountain bikers. There's lots of sources of tension between cyclists and drivers.

On a regular basis I see people racing past cyclists, rolling coal at cyclists (I can't believe that's even a term now), blaring horns, and a number of other behaviors that fall under "threatening".

US vehicles, especially pickups, have outgrown a lot of rural roads that had their origins as footpaths and horse paths. Even with well-intentioned cyclists and drivers, it's often times a setup for conflict.

I wear Lycra, ride a funny-looking carbon road bike, and average about 3,000 miles a year. In college, I rode a beater bike everywhere for transportation instead of owning a car. I’ve never experienced that kind of thing, though I’ve heard occasional stories.

Drivers don’t pay attention and seem like they’re trying to kill you, but that feels more like recklessness than malice.

I got honked at and told to get out of the road today, on a quiet neighborhood street I ride on every day.

This is true, but it varies a lot based on local culture. "Let me buzz 'em / roll coal to teach 'em a lesson"

but you're not really going to see that in, say, Seattle