I bet someone's already spotted ways to burn the system.
Up here, kids who are hard up for cash have a little trick: tie a string/bootlace to the top of a 2L sized plastic bottle (it returns 40c in credit) and put it into the chute. After it's been decoded and logged by the laser, pull it back out again and repeat the process. Keep it going as long as you can and then take the credit receipt to the cashier and grab the winnings.
The bar code can also be photocopied: take a decent quality picture of the bar code on the plastic bottle. Lay it out in photo/paint and fill the entire A4 sheet with copies you can cut out and stick to any receptacle you have handy. Shove the lot into the chute and get paid.
Hot tip: the same trick works for lots of things. I wanted AAA access passes for the Flow Festival here in Helsinki city, but they'd completely sold out the entire three day party. So I went down around lunchtime on the Friday when the construction/installation guys were finishing up. I walked up to one guy and asked for directions but slyly and silently I took a picture of his AAA and brought it home. Upload it into the computer, tone the colours and fix any irregularities in paint or photoshop, print it off and then laminate it with a standard electric iron (you can buy laminate plastic in most print shops) and hang it on a standard loop.
When Radiohead played Dublin on 'The Bends' tour, I went and bought the new single (cassette version) which came in a cigarette box-like case from HMV. Took a shot of it and uploaded it into paint. Added some detailing (Staff/AAA/Tech) and printed off just two copies. Went down to the gig, saw hundreds of people lining up, went to the stage door with a mate and acted kind of breathless and in a hurry. Knock on the stage door, glance at the doorman and continue talking about bulb replacements and electrical problems. Doorman stands aside, we walk right into the pit up front. Mate goes back out (with my copy and his own) gives it to another mate, they come in, one goes out, two come in, one goes out, etc, etc. Seventeen heads in total.
Didn't put my hand in pocket all night with the free beers.
Met Johnny Greenwood backstage with his Missus.
Showed him the blag AAAs and he cracked up.
And that concludes today's lesson.