I never quote the source of my images. Not even once - even when I use obviously copyrighted images like simpsons and disney.
Copyright law says that you can use images/text (and other stuff) for fair use. This includes for educational purposes especially when it is �not for profit�.
now there are some times when you can not use for educational purposes.
The first one is when you are using the image for a reason that competes with the original intent of the image.
For this reason MES-english has every right to take you to court if you use their images on your worksheets and upload them here. Regardless of whether or not you see the warning saying that you can not do this - it is covered by law!
This is also the reason that you CANNOT scan images or copy text from an Esl book as it directly competes with the original intent of the image/text.
I have made heaps of worksheets out of simpsons images and this is perfectly legal. I have left the copyright (Matt Groening) on the images when they are present, and I have not used the images in any way that competes with The Simpsons show. Therefore I am safe!
However - copyright law is very complicated. Disney make it so. They love to take people to court over copyright. Disney are the reason for most copyright laws. If you want to know more check out this hilariuos video which teaches you about copyright:
If you watch this film you will get a better understanding of your rights.