I found a few random good things and seen a few bad things too.
I found a nice Leatherman tool on the ground during a ride in Terra Ceia, FL. I carry it in my bike bag. Have found/seen various tools although I rarely stop for those. For some reason I see gloves on the ground a lot. During a rest break on one ride I saw one of those fidget spinner things laying on the ground. I left it, as it was at a bus stop location and sure the kid picked it back up later the same day.
Some miles from my old house one of the ride routes I took went by the interstate and a truck stop area. There were commonly a bunch of those "coke bottle meth lab" things laying around. It was bad enough at one point that as I passed by there was a HazMat team out there cleaning the area up. That lasted all of a couple of weeks before it was right back the same.