Using the wpForo plugin I don't let my users upload their own avatars directly from their computers because I'm afraid of copyright infringements, but at the same time I still wanted to give them this customization option. Fortunately wpForo allows users to simply paste the url of the image they intend to use as an avatar. I wanted to ask if this url pasting procedure works just like a normal embedded link so this means that the picture is not stored on my website thus not violating copyright laws.

If this is not the case and I am still at risk, just adding the warning that uploading copyrighted images is prohibited would prevent me from getting in trouble or not? Should I just prevent my user from uploading a custom avatar or how should I proceed?

Thank you very much to everybody who's willing to help me  to better understand this topic.