It was time to get rid of some data back-up discs. The object was to make them as unreadable as possible. May be somewhere there is a data recovery company that could retrieve the information but I guess it would be really expensive (data recovery from a crashed space shuttle). Or may be there is a hacker out these with lots of patience!
Top tip – wear gloves and eye protection when breaking discs – the technique I use is to do break them in a strong bag as this catches all the debris.