This week in social media, Facebook welcomed Tor users, while Instagram wasn't as hospitable to Chelsea Handler's boobs. Meanwhile, Twitter continued to struggle and BBM joined the Snapchat imitation club.

It's time for Social Media Saturday!

Facebook:

Facebook Tor -- Not a Contradiction in Terms 

Last week Facebook began allowing users to post under a nickname through its app Rooms.

Now, with the news that Facebook has launched a version of the social network specifically for Tor (the web browser for that "dark web" you've heard so much about), you'd think CEO Mark Zuckerberg has completely given up on the idea of battling anonymity on his turf.

But it's a little more complicated than that, as Wired pointed out. Long before buying drugs and leaking secret documents was in vogue on the Tor traffic-anonymizing network, Tor was created to keep free speech safe -- no matter from whence the user was logging in.

In fact, it was partly the U.S. State Department's project, which makes all of the FBI and NSA hackings of Tor all the more ironic. Facebook has obviously played an important role in previous protest movements under oppressive governments, like in the case of Egypt -- but until now, the site worked to make Tor access difficult.

Now, Facebook has designed its Tor link so that traffic doesn't leave the Tor network until it's within the company's domain, keeping users who may be the digital target of oppressive regimes (say, in Iran or China) safe. Until they log in and post on Facebook -- since even that special user-base can't use an anonymous handle.

Instagram -- Community Guidelines or Sexism?

We normally don't talk about celebrities on Social Media Saturday. We're interested in the systems themselves, not the people using them for publicity. But in the recent case of comedian Chelsea Handler's Boobs vs. Instagram, this particular bit of theater deserves our attention.

Long story short: Handler posted a topless photo of herself, mocking Russian President Vladimir Putin's famous shirtless horse-riding selfie, Instagram took down the photo citing its community guidelines against nudity and adult content, and Handler quit the photo-sharing service as a protest.

Handler, along with other celebrities and movements like Free the Nipple, are challenging assumptions about female nudity on social media, at a time when Facebook recently took down a profile picture of a mother breastfeeding due to similar content guidelines.

But as Charlotte Alter noted in Time, these guidelines have several reasons to exist, including serving as a bulwark against child pornography, so-called "revenge" porn, and instances where it could be both. After all, huge numbers of teens use Instagram and large minorities have admitted to "sexting" in high school.

The practical question raised by Alter: Isn't it worth it that for these sites to ban certain types of photos categorically -- simultaneously protecting those notoriously shortsighted teens and their network's reputation -- since approving or censoring photos on a case-by-case basis is simply not possible?

Another point to add to Alter's: While campaigns like Free the Nipple like to point out it's not illegal for a woman to go topless on a New York City public sidewalk, a photo of the same cannot be posted on Instagram -- remember, Twitter and Facebook are "publicly owned" companies, but they're not public spaces. Users voluntarily agree to those guidelines and terms of service when they join up.

Twitter:

Internal Struggles Bubble Up From Within

Twitter just demoted its VP of Product Daniel Graf, after only six months at his job. Graf was hired away from Google in April to help Twitter's consumer products division.

But after another disappointing quarterly report on Wall Street, Graf is being replaced by another VP, Kevin Weil, who will run all of Twitter's advertising and end user products now.

According to Re/code, over the past half-year, Twitter has replaced its CFO, fired its COO, and replaced VPs of media, engineering and now product. Maybe the IPO was a bad idea.

Saving Twitpic

Meanwhile, Twitter managed not to tick off its core veteran user-base (too much) this week, after it acquired long-time media posting company Twitpic's web domain and photo archive (and thus the links in old tweets). After fears that all previously shared photos would disappear, now it appears Twitter indeed won't be ruining that part of its legacy network -- at least not right now.

BBM:

Now With More Imitation Snapchat!

BBM, the BlackBerry messaging service -- which seems to be the only thing still popular about the lost-in-the-rough Canadian technology company -- just updated its app for iOS and Android (... and BlackBerry 10, for the half-dozen people who still use it) to enable timed ephemeral messaging.

That's right! BBM users can act like they're using Snapchat by setting photos and texts to disappear after a certain amount of time.

The ephemeral feature itself, however, is only free for a certain amount of time; after three months only paid subscribers will have access.