I'm always wary of blaming the 'victim', but sometimes a collision with someone who is behind you can actually be caused by yourself. That's why I always recommend watching the replay back after the race to see if you can identify anything you can do differently next time round. Even if it was the other driver's fault, there is often something you could have done differently to mitigate the risk of being crashed into.
Let's use an example from one of my races the other day, Manu series Gr.3 race at Deep Forest. That hairpin right before the start/finish straight can be difficult to get through cleanly if there are multiple drivers going in at the same time. In my case, I was forth in a train of four cars. Unfortunately, first place started to brake some 10 metres before they needed to, which caused everyone else to also brake too early. I was at the back of this train and was the only driver who braked at the right point, not expecting the others to brake so early, as a result I was obviously moving faster (but not too fast) into the corner than everyone else. At this point, my options are to either smack into the back of the car in front, or dive inside and hope that the car on the outside will spot me and won't try and turn in on me. Unfortunately, after I dived inside, the other driver did not spot me and ended up making contact which caused them to lose another place.
In this situation I haven't really done anything wrong, I have braked at the right spot (in fact I was actually slightly early because of the other drivers) and have done all I can, bar running my car off the track, to avoid contact. But in that moment, the driver I have made contact with perceives my actions as a reckless dive bomb. In reality there was nothing malicious about the contact and it was simply caused by a small mistake, the kind of mistake which is to be expected in a B DR lobby.
If the driver in front had attempted to defend the inside of the corner, as they should have been doing, I would have happily gone round the outside and attempted to cleanly overtake, and there probably wouldn't have been any contact.
I'm not saying there is no such thing as intentional bumping, but I think we’d all be better off if we took a more considered perspective to contact to identify if there is anything you as a driver could be doing to mitigate it. Braking too early into the corner might appear harmless but if you do so and follow the racing line, what is the driver behind supposed to do if they brake correctly? There are loads of similar scenarios where the driver behind can find themselves in a situation where it is impossible to avoid contact even if they desperately want to.