Tried that left lane block routine (only right lane open ahead) a few years back. Signs were out stating "No overtaking" so I simply paced the truck alongside me, who gave me the "thumbs up" sign.
Car behind me was an impatient off-duty Police Sergeant in a Corvette who called out six of his buddies to give me an "Impeding traffic" ticket.
Fortunately I figured out what was going on, (he stopped to talk to the cruisers) so I went to court to fight the ticket and won because I identified the off-duty cops car.
When the Judge was told whose car it was he dismissed the case and ordered the Sergeant into his chambers "Right now". I have no idea what the outcome was but I suspect he got chewed out!