Dvd’s, magazines and books are also in pharmacies, shopping malls, and other stores. All these things you fear from in a library can easily be bought or read while shopping. Do you take your kids shopping? Do you send them on their own? Where did the now 40, 50 and 60 year olds get the things they shouldn’t have gotten before dvd’s and vhs as well as internet were invented?
Teach your kids appropriately. Be the best role model you can be. Keep the lines of communications open. Let them understand the reasons why you are guiding them away from shmutz.