Top 5 for public-domain images
While the Internet is possibly the best thing that's happened to teaching and education in the last thirty years (think TES resources, Twitter, independent sites, quick communication channels), it also comes with a minefield of copyright issues. A couple of weeks before I left my last job, an email went round to all staff reminding them of copyright issues with downloading and using images from the Internet - and I used to be as guilty of this as the next person. When planning a lesson, it's very easy to just Google and pull in an image from anywhere to jazz up a PowerPoint - accessing images from all over the world means that you can easily illustrate a point about real-life applications of the mathematics pupils are studying. However, with the prevalence of online resource sharing, it's more important than ever to make sure that images used and redistributed are actually done so legally.