It’s the weekend! Before you shut down for a few days, let’s revisit some of the big stories from the week, including a debate over Apple’s new child-safety tools, Google’s interesting take on the periodic table, and Facebook’s decision to (maybe) make its advertising system care a little more about user privacy. Let’s jump in!

Apple’s New Child Safety Policy Sparks Some Privacy Debate

Apple has structured its corporate identity around privacy. It’s made a big show of preventing companies such as Facebook from mining iOS users’ data. It’s also announced a willingness to fight powerful entities like the FBI in court over encryption and device security.

So when Apple decided that it would introduce new tools to fight child sexual abuse, it did so in the most Apple way possible: iOS devices will scan photos in Messenger and iCloud Photos to make sure that the user isn’t sending child sexual abuse material (or CSAM). Like Apple’s other security and encryption efforts, relying on the device to process imagery (via machine learning) is supposed to help preserve user privacy. Only if the system detects enough matches between an image and a CSAM database is a human moderator at Apple notified. 

Other tech giants—including Facebook and Reddit—have systems that scan for CSAM, although those operations take place in the cloud. While some critics have praised Apple for taking this step, some privacy advocates are complaining that this system could be converted to target other things—people in other countries sharing politically sensitive images, for instance. 

“Instead of adding CSAM-scanning to iCloud Photos in the cloud that they own and operate, Apple is compromising the phone that you and I own and operate, without any of us having a say in the matter,” Ben Thompson wrote in a new post on Stratechery. “Yes, you can turn off iCloud Photos to disable Apple’s scanning, but that is a policy decision; the capability to reach into a user’s phone now exists, and there is nothing an iPhone user can do to get rid of it.”

Over at Daring Fireball, meanwhile, John Gruber offers a lengthy, nuanced breakdown of the issues involved. His takeaway: Apple’s new system can be an effective way to root out CSAM on iOS while preserving users’ privacy and encryption—so long as Apple resists any pressure to convert the system to track other kinds of content. “If they don’t, and these features creep into surveillance for things like political dissent, copyright infringement, LGBT imagery… anything at all beyond irrefutable CSAM—it’ll prove disastrous to Apple’s reputation for privacy protection.”

Google’s Searchable Periodic Table

You might not be a chemist—you might have forgotten everything you learned in high-school chemistry, in fact—but Google’s latest tool is still pretty cool: An interactive periodic table. Want to refresh your faded knowledge about hydrogen? Just click on that little “H” for everything you might want to know, including its atomic mass, density, and melting point.

Facebook Actually Focusing on… More Privacy

For years, Facebook has done its best to data-mine its users for ad dollars. However, with other tech companies suddenly becoming more privacy-conscious, the social-networking giant might finally be shifting tactics. A Facebook executive recently told The Verge that the company’s ad platform is being “rebuilt” to take user privacy into account. 

I think what we see in terms of the trends and frankly our own work, both from a regulatory perspective and the platforms—Google and Apple—is that access to that kind of data will become more limited over the course of the next couple of years,” Graham Mudd, Facebook’s VP of product marketing for ads, said in the Verge Q&A. “That’s just a reflection, I think, of peoples’ changing expectations around privacy. And I think we’re embracing and trying to build for that future.”

For advertisers, losing that data could have a sizable impact on the effectiveness (and cost) of their ads. But privacy advocates and everyday users will probably welcome less tracking.

That’s it, everyone! Have a great weekend!