Google and Facebook monetized child porn discovery apps, the company behind Fortnite made a lot of money this year and a new solar technology promises greater efficiency. Here's your Daily Crunch for December 27, 2018.

1. Google & Facebook fed ad dollars to child porn discovery apps

New research provided exclusively to TechCrunch by anti-harassment algorithm startup AntiToxin shows that now-removed apps that hosted links to child porn sharing rings on WhatsApp were supported with ads run by Google and Facebook’s ad networks.

In other words, tech giants aren’t just failing to spot offensive content in their own apps, but also in third-party apps that host their ads and earn them money.

2. Epic Games, the creator of Fortnite, banked a $3 billion profit in 2018

Fortnite became the world’s most popular game, growing Epic's valuation to $15 billion, but it has helped the company pile up cash, too. According to a source with knowledge of the business, the company grossed a $3 billion profit for this year.

3. A new solar technology could be the next big boost for renewable energy

Called a perovskite cell, the new photovoltaic tech uses hybrid organic-inorganic lead or tin halide-based material as the light-harvesting active layer. It’s the first new technology to come along in years to offer the promise of better efficiency in the conversion of light to electric power at a lower cost than existing technologies.

4. New e-commerce restrictions in India just ruined Christmas for Amazon and Walmart

The three main takeaways from the new policy, which will go live on February 1, are a ban on exclusive sales, the outlawing of retailers selling products on platforms they count as investors and restrictions on discounts and cash back.

5. Instagram accidentally rolled out tap-to-advance feed, removes it

Many users woke up to a shock this morning when their familiar vertical swipe stopped advancing the main feed. The company says, “This was caused by a bug and we quickly rolled it back."

6. Netflix releases a trailer for ‘Bandersnatch,’ the mysterious new episode of ‘Black Mirror’

The trailer doesn’t quite come out and say that this will be an interactive episode, but the subject matter and the tagline (“change your mind — change your life — change your past — your present — your future”) seem to be awfully suggestive.