My browser extensions are licensed under GPL. But GPL serves for code distribution not program usage.
As an example, this extension is licensed under GPL.
https://addons.mozilla.org/en-US/firefox/addon/nosquint/
But what happens if a user sues the developer for a damage that is caused by using the extension?
Which precautions can be taken for this kind of situations? Is another explicit EULA is necessary for such free GPL licensed extensions?