Examples of market failure, externalities and demerit goods

Thanks to tutor2u for these 2
http://www.scoop.it/t/marketfailure
and
http://www.tutor2u.net/economics/blog/recent-resources-on-market-failure-jan-2016?utm_medium=email&utm_campaign=Economics%20daily%20digest%20Tue%2019th%20January%202016&utm_content=Economics%20daily%20digest%20Tue%2019th%20January%202016+CID_ff11589e6f750c03a3b3ec9afced23eb&utm_source=CampMonitor&utm_term=Recent%20Resources%20on%20Market%20Failure%20Jan%202016%20Here%20are%20some%20recent%20resources%20on%20market%20failure%20especially%20externalities%20and%20demerit%20goods