Does it make sense to complain to companies about bad driving? On my commute in this morning I found myself in another situation where I was in conflict with another road user. (Briefly, a truck and I arrived at a roundabout at a roughly similar time, but I was into the junction marginally sooner and, crucially, had priority. He didn't/couldn't stop in time and only my emergency stop prevented a collision.) 

So, naturally, I shouted at him, pointing out his faults. I know this won't help the situation but adrenaline and the rush of almost being knocked off aren't great ways to start a productive discussion. We had, as they say, a full and frank exchange of views which ended with my whipping out my phone and taking a couple of quick photos of his number plate and the company name from his door. 

Realistically the police have better things to do with their time for this likely non-offence, but I did find the company's website and have filled in a 'contact us' form. I fully expect to not hear another word about it, I presume my complaint will be filed in the lunatic/whinging file and nothing will come of it. 

The question here is what should we do in these situations? We could just put up with it, going gently into that good night, putting up with a genuine belief in some other road users that cyclists are not equal peers (cf. discussions about ignoring red lights and cherry picking rules). 

Or if it's not serious enough to report to the police, am I just being too thin-skinned?
Anecdotal evidence I have heard is that in a lot of cases complaints actually do have an effect, particularly if the company is a large one.  All complaints have to be followed up and while you may not hear back from the company, management does speak to the drivers involved.  Whether this has a positive effect or just creates resentment with the driver, I don't know.