Facebook group skimming traffic?

[omikapsi]

I really don't know where this would go, or if it's even significant, but;
There's a facebook group that's posting the comics (looks like it might even be automated) but without links to the website. https://www.facebook.com/xkcdallcomics/
It looks like it's just done to share the comics, but my understanding is that when it's done without linking the original it can be a traffic loss for the website.
Don't know if that's important, but if it is, maybe someone can make a suggestion to the person who runs the group.

[Zohar]

They write the website of the group is xkcd.com so technically they are attributing it, just not in every post. And presumably this is a not-for-profit group. So I don't see this violating the license conditions.