This week in social media, publishers worried over a big shift at Facebook that could once again upend the news industry. Meanwhile, porn publishers are similarly worried about a rumored, sweeping purge of adult material and the users who post it and Tumblr launched an anti-bullying campaign.

It's time for Social Media Sunday!

Facebook:

Instant Articles Makes Publishers Fear Another Major Shift

Last week, we reported on Facebook's newest initiative in its multi-pronged plan to take over the world (or at least the Internet), Instant Articles.

Instant Articles is a feature that lets online publishers like The New York Times host their news articles and other content directly on Facebook's platform, sharing revenues from ads shown with the partner publisher. From a Facebook user's perspective, Instant Articles leads to a much faster online experience, especially on mobile, since it eliminates linking out and no loading another site.

From Facebook's perspective, it keeps users within its boundaries, whether on the app or website, which means more engagement, more user data, and more ad revenue.

For publishers, Facebook's push further into hosting news content on its own terms feels either a life raft or a boarding party of marauders -- or, more likely, a little of both.

More Privacy Pressure from Europe

As the EU begins skirmishes with various Silicon Valley mega-giants like Google, Facebook hasn't been spared from the fray. Earlier this year, the EU's privacy watchdogs officially declared its scrutinizing Facebook's collection and use of users' personal data, and now the Belgian Privacy Commission has added its voice.

See if you can spot the skeptical tone in the privacy commission president's statement accompanying the release of its 28-page report:

"The way in which [Facebook] is contemptuous of the private lives of its members and of all Internet users demands action," said Belgian Privacy Commission president Willem Debeuckelaere, according to the Wall Street Journal.

Twitter:

Adult Publishers Worry Over 'Porn Purge' Rumors

Twitter has certainly been trying its best to attract and keep new users, so cleaning up its act -- adult material generally roams free on Twitter, while more successful Instagram and Facebook have much more strictly enforced rules on explicit content -- might seem like a natural step to take.

This week, a report based on SunTrust Robinson Humphrey analyst Robert Peck's predictions of Twitter's next move says the company is likely preparing to do just that.

"Bearish investors point out that one can still see users that that are violating Twitter's [terms of service] and we would expect these users will need to be purged at some point - estimates put this users range ~10m users," wrote Peck, according to Business Insider. "We suspect this is a short to mid term issue, as longer term we presume the issue can be solved."

Despite the dry language of the investors' prospectus, porn publishers are worried about losing their accounts, and their hundreds of thousands of followers, according to the Daily Beast.

Without Twitter, where else will porn stars find an audience? Oh yeah, anywhere between the 4 and 37 percent of the rest of the Internet, depending on whose stats you believe.

Tumblr's #PostitForward Campaign Tackles Online Bullying

A new celeb-studded campaign from Tumblr is seeking to quash the meaner side of social media, enlisting the help of public figures like Vice President Joe Biden, singer Jordan Sparks, and Elizabeth Banks to take part in promotional videos for #PostitForward.

The campaign particularly focuses on using online community to create positive connections for victims of traumatic events and people with mental health problems, seeking to remove the stigma often attached and sometimes exploited by cyber bullies.

Will it work? Will Tumblr singlehandedly turn the Internet's trolls into something more like hobbits? Who knows. But any effort to make some corners of the Internet a less nasty and more welcoming place is worth a try.