It wasn't literal shit, fortunately, but it was cans. This was in south Georgia and yes. Also my experience in middle Georgia. Assholes in trucks being assholes in trucks. I'm in Colorado now and I've seen a lot of cyclists so I'm planning to test out the roads near my home in the spring. From talking to coworkers the attitude is better here.

Strangely I found when owning a smallish truck in college, strangers would apparently decide to use my truck bed as a trash bin for their various drink cans. Very strange and annoying. Random beer and energy drink cans would fly out on the highway. People just have too many cans, I guess. Maybe it's just us southern states.

If the driver in front of you loses a piece of trash from their truck bed, consider it may not even be theirs!

Well, this was obviously thrown, and on multiple occasions. I will agree that trucks get used as trash bins too much by strangers, and sometimes debris flies out. But that wasn't my experience on these occasions.