Facebook has finally responded to a number of questions that its CEO Mark Zuckerberg batted away during a marathon Congress hearing in April, outlining the extent to which the tech giant tracks its users.

In the answers, the social media giant revealed that it can track users’ mouse movements and text message logs, how its NewsFeed ranks different posts and its use of security app Onavo.

Zuckerberg faced a grilling from US senators earlier this year after the Cambridge Analytica data harvesting scandal.

But the founder declined to answer many of the more difficult questions that were posed to him, saying he would instead have his team “follow up with” the senators.

Two months later, US Congress has now released the written responses provided by Facebook to the questions, with nearly 500 pages providing insights into how Facebook tracks individuals all around the internet.

In one of the responses, Facebook revealed exactly how much data it collects and tracks on users who consent to the broadest range of collection when they sign up for the service.

Facebook tracks users’ apps and file names, available storage space, mouse movements, information about web-connected devices, every IP address used when signing into the platform, the device’s connection speed, purchases made on off-Facebook sites, call logs and SMS history.

The company was at pains to emphasise that users have to provide “consent” for this level of data collection.

“All users must expressly consent to Facebook’s terms and data policy when registering for Facebook,” the company said.

“We collect the content, communications and other information users provide when they use our products, including when they sign up for an account, create or share content and message or communicate with others.

“We collect information about the people, pages, accounts, hashtags and groups users are connected to and how users interact with them across our products.”

Facebook also said that it had offered the same support to the Trump and Clinton teams during the 2016 US presidential election.

“Facebook offered identical support to both the Trump and Clinton campaigns, and had teams assigned to both,” it said.

“Everyone had access to the same tools, which are the same tools that every campaign is offered.”

The company also further explained how its NewsFeed prioritises stories since it was tweaked to favour content from friends and families rather than news outlets.

It said the “ranking” process has four elements.

First, an inventory of stories is fed into the algorithm, which then finds “signals” or data points that can inform the ranking, such as how old the post is, who posted it and how fast the user’s internet is.

The algorithm then determines how likely a user is to share or comment based on their past behaviour.

This information is then combined into a “relevancy score”, with posts on the NewsFeed directly ranked by this number.

In its answers to Congress, Facebook confirmed that it does use data from security app Onavo to see what other products and platforms are popular among its users, but claimed it doesn’t connect this to individual users’ profiles.

Facebook acquired the Israel-based app develop in 2013, and senators wanted to know whether the company has been using the traffic data it collects to “monitor the adoption or popularity of non-Facebook applications”.

“[Facebook] does not use Onavo data for Facebook product uses, nor does it append any Onavo data or data about individuals’ app usage to Facebook accounts,” the company said.

The social media giant said that it “communicates repeatedly and upfront” that it owns Onavo.