This is controlled by the website that you are using. Based on what you have described, it sounds like you are referring to Facebook.

Unfortunately, that behaviour is entirely controlled by the website, not Firefox.

No, this is when I copy any story with links in it in responding to the YahooGroups I participate in. I'm not on Fakebook, Twaddle or any social regurgitation sites, this is simply copying an article and replying as an email, and it does it on any articles I copy that have embedded links. This never happened until I upgraded to the latest Firefox, so I know this is a Firefox problem.

It's still not a Firefox problem. Facebook is an example that I used. A variety of other websites (social networks, forums, email websites, etc.) do the same thing.

There is no feature on Firefox that would add this functionality. It's entirely dictated by the website itself.

If it only started after a recent update, it's either a coincidence that the website developers added this feature during that time or the website developer (for some reason) only rolled out the feature to newer versions of Firefox.

Thank you, but obviously you don't know what you are talking about. So all of a sudden EVERY news site that I pull articles from started this at the exact time I upgraded Firefox. Right.

Does anyone else have an answer?

To clarify, it's the website that you are posting the link to that has this new feature, not the website that you copied the link from. It's a common feature. The website you are posting to simply detects when you have entered a link and then looks up the information for that link, similar to how a search engine does.

An easy way to prove that this isn't Firefox-related is to try in another browser like Internet Explorer, Microsoft Edge or Google Chrome.