If you reference a blog post or webpage, can you also legally use an image on that webpage in your reference?

[Jordan]

This is a question I've been trying to figure out for a while.

On websites and services like Facebook, Feedly, Buffer, or other RSS-readers, they pull images from a webpage and display it on their site or service. For example, if you share a page on Facebook, it will pull the Title, some of the Text, the URL, AND an image from that page.

So, incidentally, they just used someone else's image that they have no license for on their website, simply by not taking credit for that image, and directing immediately back to the original source.

What gives them the right to do that?

I ask because I am making a website where I share and reference important news posts from around the internet, and I would love to include a graphical element, but I would rather source myself properly for protect, rather than contact every original author, finding creative commons images, or taking/purchasing relevant images myself.

Long explanation, but I hope you can help! Thanks!