I've heard mixed reviews as to how secure they are. The locks look fine but I've heard that with two pairs of pliers you can remove them fairly easily, but this is just hear say... Personally I use fairly cheap Allen key skewers which to my mind whilst not a deterent to a professional (or reasonably determined)thief will probably stop casual theft by kids.
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Currently riding an MTB with a split personality - commuting, touring, riding for the sake of riding, on or off road :)