Most popular website are tracking your mouse movements and clicks on their website. It's called a user heatmap and it's meant to be used to see what users are actually clicking on when they drop into your website i.e. everyone highlighted this word on you copy or stopped scrolling after this section that sort of thing.
It's been happening for many years. If you don't want to give websites this data block javascript in your browser by default.
Seems fairly sensible to figure out how to optimise the ui
They don't record information typed into forms, e.g. addresses, emails, CC numbers. Well, some don't record by default, with others you have to specify that manually.
Either way, it's better than a Facebook or Twitter Like buttons that infest the web and connect your visits with that site to your Twitter/FB account.
It is. Everything you do is being logged and categorized, and your automatically assigned device fingerprinted user UID (whether you've made an account or not), is associated to all of your actions. Those associations are then dumped into a data lake for data scientists to mine for marketing purposes, and to cross-reference your activities across other sites.
I'm sure some sites don't do this, but plenty do.
Check out FullStory. It's a drop-in Javascript snippet (aka accessible to any marketing/design folks) that records the DOM and rebuilds it as a playable video in their backend as if you were doing a screenshare and recording it.
It's even worse than this. They have full HD screen recordings of every single user session, including all values typed into any input field regardless of submission. I can pull up hundreds of thousands of unique user sessions right now and sit there watching everything they did on our sites, going back for years.
Say it with me now:
Every. Single. Interaction. With. Any. Computer. Is. Tracked.
It's not anonymous and it's not just buttons. Furthermore it comes down to consent. I can see the cameras in the shop. I have no idea without doing network traffic analysis what kind of surveillance is happening on a website.
If you store and mouse movements, scroll events, clicks ...etc and you know what the website looked like then you can replay these to produce something that looks like a video. The bonus points is that you can run mathematically analysis on the clickstream to get things like most clicked area and suchlike.
It's actually the same data that's used in the heatmap just a different visualisation.
Most heat mapping services do not store such qualitative data because of the cost (e.g. hot jar). They opt instead to simply reproduce the "almost full story" by faking a video from the data. Services like fullstory are different.