Oh, sure, we all dance around the “educational use” sorts of excuses. But it won’t be hard to find more than a handful of examples where the boundaries of educational use are pushed against or totally crossed over.
I’m not saying you have to go back and trash everything you’ve done, but you can take a go-forward approach to making sure that any new materials you use are truly legitimate.
To help, here’s a huge resource of place to find Open Educational Resources. Pictures, videos, material, books, etc. all made available and deliberately set up as ‘free for the taking’ (or the most it requires is an attribution — hey! we talk to our students about plagiarism; let’s walk the walk!). Take a look at it and see what you can find.
If you find something cool, let me know!