I'm often asked by Parents and Care givers "how do we protect our young adults and children" from the lawless internet..especially restricting access to adult material and porn?" Unfortunately, humans are very resourceful critters and usually find ways around barriers -given enough time.  My advise, educate them and set guidelines.  Try some of these ideas in the article.  There is no silver bullet but these links will give you a few things that you could try to "make it more difficult'

Check out https://www.opendns.com/ 

and take a look at these ideas and suggestions for specific platforms

 

• http://www.mirror.co.uk/lifestyle/family/how-to-block-porn-sites-from-kids-841870

 

• https://www.vodafone.co.nz/help/mobile-safety/advice-for-parents/

 

• http://www.spark.co.nz/help/internet-data/manage/how-can-i-keep-my-kids-safe-online/