I would definately say don't over do it, I tore my ACL, MCL, Meniscus because I would go balls to the wall on my leg exercises and at a soccer tryout tried to cut while going full speed.
When you are in a situation asking for injury then yes, you should back off, however I was referring to non threatening situations where there is no reason to want gains to come slow. When you lift, lift correctly and enjoy whatever gains you get.