Is reposting funny pix on a "Facebook Page" copyright infringement?

I run across a lot of “Facebook Pages” that are both fully public and consistently posting things from all over the web. Isn’t that technically copyright infringement? I see these crazy e-cards from rottenecards.com and someecards.com all over these Pages. I guess you could argue that it drives visitors back to the source site, but if you republished an article from the New York Times without permission, you would get an immediate take-down request. Is it just the Wild West on Facebook?