On a similar (but tangential) note: US currency notes have similar yellow circles, which are detected by photocopiers, which, in turn, then either (a) refuse to photocopy them, or (b) mangle the copy (put vertical bars through it).
Try photocopying a $20 bill on a copier and see for yourself.
I doubt that the Secret Service will get there quickly enough to arrest you. I also doubt that they would have enough evidence to arrest you for anything. Putting a $20 bill in a copy machine is not a crime.
I did that with a $50 bill once on my company's big office copier just to see what it would look like (uh, I swear) and was pretty floored when I saw the copy come out with stripes through it. I tried it with every other denomination I could find, and if I remember correctly bills at or below $5 don't have that feature (at least not at the time).
Try photocopying a $20 bill on a copier and see for yourself.