Much like Santa Claus, who knows when children are sleeping and when they are awake, Facebook has been keeping very close tabs on me and everyone else.
It knows what kind of phone I use, who my provider is, that I live away from my family and that I have friends who are fans of British soccer.
And it uses that information to advertise to me.
Similarly, many old and long-unused apps still have access to my data after I used my Facebook login to access them. I granted permission years ago and then forgot they ever existed.
This in and of itself isn't totally nefarious - after all, if you aren't paying for a product, you are the product - but the sheer amount of categories Facebook was able to correctly identify I fit into was creepy.
In the wake of Cambridge Analytica scandal, where it was revealed millions of users' data gathered on Facebook was improperly accessed by a third party to possibly influence the United States election, I explored the settings page on my Facebook profile to discover what Facebook knew about me.
I also made it as private as possible. A starting point was turning my location off in the Facebook app.
Netsafe boss Martin Cocker said a certain level of data exchange was the price we have to pay to use a free service but we could minimise the amount we volunteer.
A lot of data people gave willingly so they could access a platform, but what people perhaps weren't so aware of was that platforms track their clicks, their scrolling, where and when they logged on, Cocker said.
"All those things provide data points, if those businesses want to capture them, about what sort of user I am."
Then there were third-party apps - services people had downloaded to their phone, granted access to their information and then forgotten about.
"When you install apps they ask you if they can have a set of permissions," Cocker said.
Usually the option was to either accept or reject the terms.
"If you really don't want to give that permission - you use another product."
Similarly, when Facebook updated or changed anything, take the time to read the details of the changes, Cocker said.
"They do try to communicate them, and they do try to communicate them in terms we understand."
The long and short of it is if you want to keep using Facebook, there's no getting around the fact some of your data and information will be collected by the platform.
However, now is a good time to take stock of exactly what Facebook can see and which third parties have access to the information the social media giant collects.
While you're at it, you might as well double check what strangers can ascertain from a quick glance at your profile as well.
HOW TO ENHANCE YOUR PRIVACY:
Go to settings on your phone, and click "apps". Every app listed under the heading "log in with Facebook" has access to your data, which you can change by altering the permissions.
You can also delete an app completely, though this doesn't delete data the app developers may already have about you.
Then, go to the ads tab - it's directly underneath the apps tab - and click.
You will see a "your information" bar which can be unfurled to show "about you" and "your categories".
Toggle every profile field in "about you" to off where you don't want to receive targeted advertising in those fields.
"Your categories" is based on your friends list, jobs and education information and location info, which Facebook uses to add you to categories for targeted advertising.
You can manually delete the categories one by one.
Below the "your information" bar is the ad-setting bar where you can opt out of being shown advertising by certain parties by clicking "no".
Finally, go to the privacy and timeline and tagging tabs in settings and check your account is as private as you'd like it to be.
Things like who can see your friends' list and your posts can generally be set to friends, public or just me.
Face recognition can also be turned off.
HOW TO REDUCE THE AMOUNT OF INFORMATION FACEBOOK CAN COLLECT ABOUT YOU:
Turn off the Facebook app's ability to know where you are at any given time. To do this on an iPhone, go to settings, then click privacy, then location services.
A list of apps will appear, and each can be toggled to adjust when that app can access information about where you are: either always, only while you're using it, or never.
On Android, go to settings and click application manager. A list of apps will appear including Facebook. Click it, then click app permissions.
Toggle the location permission from green to grey by sliding left. This will turn the permission off.
TO DOWNLOAD A COPY OF YOUR FACEBOOK DATA
Go to settings and under general there's a hyperlinked option for download. Click and follow the prompts.
This won't do anything to enhance your security, but exploring the saved data once it's downloaded will reveal just how true the maxim is that nothing on the internet is ever gone forever.