Nothing like watching railfans, workers, and some foamers argue the legalities because absolutely no one here has ever trespassed on RR property, ever
Really though I do enjoy seeing people discuss & explore the topic. It may, or may not, be worth noting that the tradition of hoboing and its associated behaviors predates most anyone on this site, and the attitude toward riding freights is quite varied just within the RR itself. I myself was surprised to find out just this year that a retired engineer I know rode freights before he came to work for the RR. He said he never forgot his experiences hopping freights and was always willing to help a guy out if he saw him. There are also plenty of workers willing to give out info, like are there any Westbounds leaving today? As for hobo marking and monikers, some of the most famous ones associated with hoboes were actually done by workers (see Who Is Bozo Texino? by Bill Daniels on Youtube) and I sincerely doubt that stopping hobo monikers is a big priority when workers write on the trains and other areas too.
Some workers are of the attitude that if a man can safely get himself on/off the train and through the yard then they are free to ride. I've had others tell me they don't have time to keep running back to check their train so if someone makes it on, they're rolling with them. I was present in the Midwest when one guy phoned in to the crew of a passing train to let them know he would be boarding the 3rd unit as they passed- and he did! Of course I've seen people kicked off or arrested and some areas are tougher on this than others.
For all the hobo/freight riders I've met, I've never felt in danger at all. If anything, they may have been more a danger to themselves than others, usually with the younger crowd that gets drunk around the tracks leaving them prone to injury. Most of these guys have no desire to be seen by, or to interact with, railfans as they figure you're going to tell on them. They're just trying to catch a ride without being seen by anyone.