What? I don't usually stole anything, but I'd do it in this case XDDD

Reminds me of this publicity stunt, ugh I'm old, that was 20 years ago already.
http://www.nytimes.com/1995/09/27/nyregion/steal-these-pants-ad-pulled-so-new-yorkers-won-t-try.html

It's a double-edged sword for scalpers. On one end, you might be able to scalp it for a a shit 💩 ton. On the other end, you will easily be singled out for trying to sell stolen goods.

General rule at trade shows or conventions is if it is not nailed down or too heavy or bulky someone will think it is swag and try to take it.

indeed, they would have to resort to awkward explanations like "me? no, ofcourse I wasn't at an Xbox One event, I stole the glass from someone who stole it from there" to save face /jk

This is advertising. Not only do they not mind if you take it, they want you to take it. It's not like they're going to wash them, pack them away, then ship them to the next event. If people don't take them, they'll be thrown away.

Lots of places do this with advertising, by the way, especially with pens.