I went to Rome earlier on this month and you have to go through security checks when visiting the Vatican museum. When we went through the metal detector it buzzed but the security guard was pretty relaxed and asked us if we had any metal object on us. We pointed to our kara's but did not display our kirpans and he was happy for us to go through.
There were also security checks to enter the roman forum and the guards here were also pretty relaxed.
There were also security checks before entering the Colosseum. The security guard here asked us to remove our kareh but we said that they don't come off. They then got one of us to walk through the metal detector but keep the hand with the kara on out of it so that they can check if you have any metal on your body. Luckily the first member of our group was only wearing a kara and no kirpan, so he went through without setting off the metal detector. Because of this the security guard then let the rest of us with kirpans on through without searching us.