Here’s a link to the Top 10 Copyright Myths prepared by the UK Copyright Service (aka Copyright Witness). In addition to being a copyright registration facility, they also aim to educate and increase awareness via information pages and fact sheets.
I particularly noted the following myths:
#4 Everything on the internet is ‘public domain’ and free to use – Wrong. It may be publicly accessible; but it is not in the public domain
#5 Anything without a copyright notice is not protected – Wrong again. Copyright will apply whether there is copyright notice or not.
#9 It’s hard to prove copyright infringement – Not true. Copyright law is civil, not criminal and requires a lower burden of proof.