To start with no level of security is full proof, but that does not mean we leave our front door wide open. As a photographer I use a plugin to deter people directly copying an image, is it fool proof, no but its a case of not leaving my front door wide open. On user experience, its a choice every designer makes as the same way no security is fool proof, no design is entirely perfect there will always people people you can't satisfy, that's why we do research to find out who the core users are. Am I concerned stay at home mum can navigate my site, not really, as long as an event manager can!