This may not affect you, but flying from Shannon to London on Aer Lingus 3 years ago, the Shannon airport security wouldn't allow any "tools." I was carrying my bicycle mini combo-tool (compact device with wrenches, screwdriver, bottle opener) which had not been a problem leaving or entering the USA or England, but Ireland prohibits "tools." The most I could've done onboard was maybe loosen the tray table in front of me, or poke my seatmate, but for them a tool was a tool. Arriving 2 hours prior to take-off, I was able to find a small box at the airport, put the mini tool in it, and check it before the flight took off. Our passports were stamped.