I was recently travelling from St Pancras to Lille on Eurotar. I had my Opinel penknife in my case and this was picked up on xray and confiscated. They could not provide any explanation as to why it was "illegal" to take a French penknife back into France. They did tell me that it would be quite OK to bring the same knife back from France to the UK on Eurostar. They also said It go in a special bag for £18 !
None of this makes any sense to me. Can anyone shed any light on the legality of this confiscation.