So as part of one of my presentations, I've started using a pair of handcuffs (don't ask, it's a long story but it certainly perks the audience up!). These are not official police issue or anything, they're bought from a toy store and while they have a teeny key, I always throw that away and just use the small catch on the side to open them. This is it. (singular, referring to the 'pair' of handcuffs - looks silly but I think that's correct grammatically)

I put them in my carry-on, and then cross my fingers and hope.

Heathrow has no problem with them at all, which is useful - at least I can get them there.
Istanbul took them off me, but at least when I checked the airport website they do list 'restraints including handcuffs' on the prohibited list.
Paris and Frankfurt - fine.
Dublin and Nuremberg - confiscated.

And the guy at Nuremberg told me that this was a European-wide thing - he was amazed when I told him that I had no problem at FRA, CDG or LHR.

Does anyone know if there are any 'standard' protocols on restraints in carry-on? I think I saw somewhere a TSA list which definitively put them on the allowed list for the USA, but in Europe there are only ever 'prohibited' lists which all contain the cop-out line 'this list is not definitive'.

Will I just have to keep shelling out $5 each week for a new pair?

Aarrgh.