My new mantra is "just because you can, doesn't mean that you should". Just because you can easily speed on that residential street, doesn't mean that should. Similarly, just because you can easily copy and paste an image from the web, doesn't mean that you should. First and foremost, you need to accredit the source of the information. But you also need to be looking for obvious copyright restrictions, obvious pay walls, potential digital locks and also ensure that it is a legal copy.
Many things to consider, but copyright doesn't need to be a huge burden.