A group of British MP’s, seemingly upset at Facebook CEO Mark Zuckerberg’s refusal to appear before the U.K. Parliament, have released a cache of seized Facebook documents. The documents outline many of Facebook’s practices around advertising.

BBC News reports the U.K. Parliament’s fake news inquiry has published a number of seized Facebook documents, which include emails between senior members of Facebook staff and other employees. The cache — which is approximately 250 pages long and was marked as “highly confidential” — was obtained from Six4Three, a startup app company that is suing Facebook.

One document from the cache is allegedly the contents of an email sent by Mark Zuckerberg outlining how Facebook could press advertisers for more money to access user data, saying: “Reading anything, including friends, costs a lot of money.”

Exhibit 170 – Mark Zuckerberg discussing linking data to revenue

Mark Zuckerberg email – dated 7 October 2012

‘I’ve been thinking about platform business model a lot this weekend…if we make it so devs can generate revenue for us in different ways, then it makes it more acceptable for us to charge them quite a bit more for using platform. The basic idea is that any other revenue you generate for us earns you a credit towards whatever fees you own us for using plaform. For most developers this would probably cover cost completely. So instead of every paying us directly, they’d just use our payments or ads products. A basic model could be:

Login with Facebook is always free

Pushing content to Facebook is always free

Reading anything, including friends, costs a lot of money. Perhaps on the order of $0.10/user each year.

For the money that you owe, you can cover it in any of the following ways:

Buys ads from us in neko or another system

Run our ads in your app or website (canvas apps already do this)

Use our payments

Sell your items in our Karma store.

Or if the revenue we get from those doesn’t add up to more that the fees you owe us, then you just pay us the fee directly.’

Damian Collins, the chair of the Culture, Media and Sport select committee, used a rare and unusual parliamentary mechanism to force the founder of U.S. based software company Six4Three to hand over documents relating to Facebook when he was visiting the U.K. on a business trip recently. Parliament went as far as sending a sergeant-at-arms to the software company founder’s hotel with a warning and two-hour deadline to comply with its order and hand over the documents. When he failed to do so, he was escorted to Parliament where he was informed he faced heavy fines and even imprisonment for not complying.

“We are in uncharted territory,” said Collins. “This is an unprecedented move but it’s an unprecedented situation. We’ve failed to get answers from Facebook and we believe the documents contain information of very high public interest.” Collins stated that Zuckerberg’s refusal to testify before the U.K. Parliament and testimony from a Facebook executive in February which they found to be misleading has forced Parliament’s hand in the matter.

“We have very serious questions for Facebook. It misled us about Russian involvement on the platform. And it has not answered our questions about who knew what, when with regards to the Cambridge Analytica scandal,” he said. “We have followed this court case in America and we believed these documents contained answers to some of the questions we have been seeking about the use of data, especially by external developers.”

The full cache of Facebook documents can be read here.