This week Columbia University's National Center on Addiction and Substance Abuse (CASA) in the US released a poll of more than 2,000 teens that found that spending time on social media sites such as Facebook and Twitter can lead to smoking, alcohol, and drug abuse.

"Be afraid of Facebook, be very afraid," jokes The Huffington Post, citing the claims as "outrageous." "It's another correlational study in which the reader is obviously supposed to assume causality, a no-no in the world of studies," adds the Los Angeles Times. "At one time, public health experts thought that eating ice cream might cause polio; they noticed that the number of polio cases was higher in places with greater ice cream consumption."