I was at a the Open Compute Summit that Facebook hosted in NYC, and one of the data center executives was sucked into a sales conversation and sold quite flagrantly, interrupting our group's conversation. At an industry event where people have paid admission fees and/or exhibit fees many sales people think it is their right to sell the attendees. You have little hope of doing anything to get an aggressive salesman to leave you alone.
Then it hit me after the salesman left. We should have yellow and red cards for attendees to flag fragrant behavior. I've order a few of these for a group of us to use in a week.
We are hosting our own event, so we can create our own rules. We'll have fun with this idea.
Here is the record for yellow and red cards in a soccer match.