To the bolded; absolutely not the only solution for "safe operation," and ridiculous overkill if the rest of the industry is any example. So, you're suggesting that Kings Island and Cedar Point, Knott's, Magic Mountain, etc. don't operate their rides safely as they don't have metal detectors at any rides, or even nets (or other coverings) over walkways where some rides travel in some cases? There are plenty of other coasters with vertical lifts, but I can't think of hearing any serious problems with items falling from them. That section won't be flinging anything like a projectile, so a good net should take car of falling objects short of an open knife (and if you have an open knife in a pocket on a ride, well, you're just dumb). The real "problem areas" are things like Hulks 0-G roll (there's a net), the Dragons passing by the exit path (extend a net above the fence if they're that paranoid), Rockit's treble clef and crowd surf elements (nets in both areas already). I don't see where they're any less safe than the previously mentioned parks. There has just been a string of bad luck with an overreaction. I can't imagine that Universal is the only park to have had incidents where loose objects from riders have hit or come close to hitting someone. That would just be ridiculously bad luck, and pretty much statistically impossible. Yet they are the only park to react to such incidents in such a severe way.