Swiss Cards are another item that can land you in trouble with the nanny-state laws.
A handy little item that you can keep in your wallet or purse, they draw the attention of airline security and you can miss a flight if you don't bin it. There could even be charges laid, even if you DO bin it:
http://mypolice.qld.gov.au/mackay/2014/11/26/notice-appear-court-knife-possessio... There are a number of types of these cards, but the Victorinox I used to carry all the time does possess a (VERY) small, sharp blade. When one considers that the blade, plus handle, fits into a small, thin card - well, you just
know that it has lethal capability.

I, myself, need to buy another cane knife, a Spear & Jackson SJ-2100615:
https://www.toolmart.com.au/sj-2100615.html For $35 it's a very handy tool around the yard. It'll drop a foot-thick banana tree in one one swipe, which is a pretty good effort if you've ever attempted to drop a banana tree.
Funnily enough, Brisbane City Council issues (or used to) their workers with a stainless steel lock-back single-edge knife with a 75mm blade. I've got one I carry at work (and to and from home).
Are these items then considered legal because one is used in a profession and the other used as a garden utensil?
Obviously you don't carry a cane knife down the street, but what about the pocket knife?
I also used to carry a Leatherman on my belt when motorcycle riding, albeit a 30 yo motorcycle. is that considered a tool or a weapon?
One remembers the old aluminium combs with the sharp handle.
Just sayin'.