Are dashboard cams widely used in the trucking industry?

Good idea! I can also see them useful to pull off the dash and document other transactions to cover your ###. Also, I think I would put some kind of notice on the side of my door "Video device in use, your actions are being recorded" just too keep the lot scum on notice not to act too obnoxious around my truck. I think the light of the digital cam display would help to bring this point home. It would not be foolproof for this, but it would add one more level of deterrent.

It is just speculation and I respect your opinion, so I can not argue my point that I think they will be required on all vehicles in too strong. However, just in the interest of a good discussion I will say I think the legal obstacles are not so very high to require them. If you are on a public roadway, your right to privacy goes down a big notch and as we all know driving is a privilege, not a right. So if a State(s) decide to and have public backing to require them, just like seat belts, I think they can do it. The younger generation has grown up with electronics integrated into their lives, I think they would accept a video dash cam requirement. Also, it seems like they are widely used (required?) in commercial vehicles in parts of Europe. If you go on YouTube, you will see tons of accident and “fail” videos taking place on Europe roads using dash cams.