At Tegel, we left from terminal C which is a small temporary hangar, only our flight and one from Bulgarian Air was operated from there when we took off. We checked in and gave up our luggage, got a coffee and 10 minutes later I heard my name called on the PA. I went to meet 2 police officers. The woman asked me what was in my large suitcase and I tried my best to list it; a few old digital cameras, some video tapes, a harddrive, some tea, coffee, some chocolate and gifts, a couple of musical electronics toys, an mp3 player, some other electronics and lots of cables, and clothes. They said they were unsure about one item and decided they wanted to open it so we walked to a security check room. They scanned the bag again and then opened it. I started to describe the electronics, but they just said they were concerned with one small thing and pulled out a little bundle, a cable, some small electronics components, a 9V battery and my Arduino and asked me what it was. I told them it was a home-made connector attaching a computer to other electronic items and they I used it when making electronic music. They named it an adaptor and told me I should not pack all the parts together, but rather to put the cable, battery and the components separately in my luggage and maybe to put the board into my hand luggage or another suitcase to avoid future suspicions. So I took the board with me and they took my suitcase (I hope) back to the luggage truck and I went on to pass through the personal security scan. This is operated by a security company, not the police. When I got there, they again scanned my hand luggage many times and asked me to take out the small package, with the Arduino. I told them it had just been inspected, but they said they needed to sniff it again. I had to go into another little room and they used a little tissue and checked something with a machine. I'm assuming they were looking for explosive powder or something like that. The inspector again asked me what it was for and I told her the same as the first and she said that it looks very suspect. I remembered then that once my bus was delayed for 2 hours at the Bulgarian/Macedonian border because of the very same Arduino. Has anyone else had any problems in travel with their Arduino? All my harddrives, ipod and small digital cameras we not at all a problem, only this alternative technology made the security guards nervous. I wonder how I would have been treated if I was a different person, , if I had acted nervously, if I was a man, if I had a beard, if I was arabic, if I wasn't a Canadian girl who is used to and stays relaxed in(and is even amused by) strange travel situations…?