Never happened to you? Well, it turns out that there is a deal of confusion and beer based debate around the topic and it isn't just because people have had a few too many tinnies at a party.
Different recyclers operate in different ways, collections are facilitated and treated differently and technology is constantly changing. As a general rule set however it really doesn't matter if you crush your cans or not. (If you have ever worked in hospitality you would know that pretty much every vessel that can be shrunk, bar glass, has the air taken out of it because space is a premium.)
Aluminium cans are processed using an ‘eddy current’ to remove the aluminium. Basically the system applies a static electricity charge to the cans and collects them like a magnet. The process is automated, and the ‘eddy current’ doesn't care if the can in crushed or not. (Plastic bottles are sorted using infra red separators and can also be crushed. The only container you should never crush is glass.)
Please don't put foreign objects inside cans, crushed or not, as they contaminate the recycling pile. One of the most common is plastic straws, but cigarette ash and butts figure pretty highly as well. A do pieces of lemon in beer and some sodas.
So party goers, whether you are a can crusher or a bin basket shooter, either is fine. Just don't use your can for an ashtray or leave your food or straws in them.
Images: Stone & Wood / Unsplash | Blake Guidry