Don't know if it's still random, because I haven't been there since last July. It was random then, but a lot of people got picked. I wouldn't fret over it or try to be "prepared". It's not all that big of a deal, plenty of people with that similar situation go through, and security is quite used to it. I have pins in my hip...not sure if they set off detectors or not, but either way, it's no big deal.