I found this of interest. Whilst it has a US focus, it sets out some useful principles to consider. From David Coen of PikWizard:
PikWizard’s guide How Photography Copyright Laws Affect What You Share Online explores everything you need to know about copyright infringement. It covers what copyright infringement is and how copyright infringement works.
It can be hard to tell if you’ve used copyrighted materials without permission before. There are a few things you need to remember: photography copyright is automatic, and you don’t need to use the copyright symbol to protect your photography portfolio.
If you are unsure whether to use someone else’s photography, it’s always best to ask.
This guide also covers how copyright is created, the benefits of registering copyright photography and protecting your work online.
There is also an infographic on the post which has some helpful reminders.