Ask privacy advocate and Facebook critic Mark Weinstein what kind of information the social media giant has on its users and he responds with a blunt, one-word answer: "Everything."

That may be somewhat hyperbolic, but it's certainly fair to say Facebook holds a lot of personal material. That data collection, and the sharing of it with other firms, continues to be controversial.

On Wednesday, the New York Times reported that Facebook gave some companies more extensive access to users' personal data than it has previously revealed, letting them read private messages or see the names of friends without consent. One of those companies, the story alleged, was the Royal Bank of Canada.

The Royal Bank of Canada disputed the report and the suggestion that it ever had the ability to view users' private messages.

The Royal Bank of Canada disputed the report and the suggestion that it ever had the ability to view users' private messages. (Nathan Denette/Canadian Press)

Meanwhile, Facebook disputed the allegations that it gave some companies carte blanche to access user data. In a statement to CBC News, Facebook said its corporate partners "don't get to ignore people's privacy settings, and it's wrong to suggest that they do."

Still, the New York Times report raises questions about what information, exactly, Facebook has about you.

Here are some answers to basic questions about what information the California-based social media giant retains:

Ok, so as a Facebook user, I get that it records my basic profile information and Facebook activity. But what exactly does that include?

It includes quite a bit. At the very least, Facebook has access to the information that you provided to them directly, including profile information, email address, friends and contacts

But it's more than that. Facebook itself includes details of their collection policies on their help centre page under the heading: What categories of my Facebook data are available to me? This includes:

Dates, times and titles of ads clicked.

All of the apps you have added.

A history of the conversations you've had on Facebook Chat.

Email addresses added to your account (even those you may have removed).

Events you've joined or been invited to.

IP address, dates and times associated with logins to your Facebook account

Can I find out what information Facebook has on me?

Yes. On Facebook, you can download a copy of the data the company holds about you. Users can save the archived information to their computer on a zip file, including material "about you," calls and messages, likes and reactions, payment history, search history, your places and ad interests.

Is that all they've got?

No. Ashkan Soltani, a technologist specializing in privacy, security, and behavioural economics, said Facebook also has information about your behaviour or "passive activity." This includes how long you look at something online, whether you hover on a video and what ads you look at.

Logging on to Facebook will allow the company to know your location. If you have a Facebook mobile app installed, the company knows your GPS coordinates and what you are visiting.

"So when you walk into the coffee store, when you walk into a stadium, that information will go to Facebook and Facebook will know that you're attending something or you're buying coffee," Soltani said.

How about my activity off Facebook?

They know that too.

"They know a lot of what you do around the rest of the internet by way of third party tracking networks," said Bennett Cyphers, a staff technologist with the Electronic Frontier Foundation, a California-based digital rights group.

If you're accessing the internet on a browser or mobile device you have used before to log into Facebook, the company can link that to your actual account. They do this by using an invisible "pixel" — essentially a piece of code that Facebook convinces web site owners to install on their pages. That pixel allows Facebook to know if a Facebook user has visited that site.

So if you're not a Facebook user, Facebook has no information about you, right?

Wrong. Facebook maintains what have been referred to as shadow accounts. This is information that Facebook has been able to collect through the friends of a non-Facebook user, if those friends use the social media service.

Facebook can glean information about you, even if you're not a Facebook user. (Dado Ruvic/Reuters)

For example, if a friend, who is on Facebook, adds you to their address book, uploads your photo or tags you, that information will be made available to Facebook. Similarly, if your Facebook friend calls or messages you, their activity log including your information will be available to Facebook.

"If or when you do sign up for the first time to Facebook, they can link the data they already have about you to you and populate your account," Cyphers said.

Soltani said Facebook can also track a non Facebook user's browser uniquely, through those pixels. "And that information helps them build a general profile about what people like," he said.

With files from The Associated Press