A few websites have started including javascript that can detect when devtools are open, thus making it harder to verify their activity among other things.
In most cases it seems that they implement the project `disable-devtool`, which uses the detection methods found here: https://github.com/theajack/disable-devtool/tree/master/src/detector/sub-detector
An example of a site using this in the wild is vidsrc.to.
This ability to detect devtools has been opened seems like unintended behaviour and counter to the user's best interest, as websites can change their behaviour to avoid detection of unwanted activity or even just prevent inspection altogether.
My hope is that preventing detection is a relatively simple matter and that the Firefox team decides to fix this behaviour.
