Even as a bush pilot on the C208 I had my leatherman in my flightbag. However, as a passenger I never took it as carry on luggage. In Copenhagen they made me take it out and at LHR there was a poor little cardboard box on the conveyor belt with my leatherman in it. Don't expect everyone to be so generous.
The fact that there is a crash axe in the cockpit is not an arguement as security have a job to do, and no knives. As a pilot I've never had grief about my leatherman in my flightbag, even when in 3rd world countries, but then I didn't offer that info, not that I'm saying SpootNICK did.