I had it the SSSS at KEF when flying Icelandair last year. It was definitely a PAIN. After I was pulled aside in security, I had to wait in another long line to be seen. After finally being taken into a private room, they went through every item in my bags very diligently, including showing them that my electronics turned on and "looked right", along with checking all of the clothing I was wearing. I just made it to my flight, and others in that long line definitely missed their flight.