Apple is notorious for kitting out its products with anti-tamper fasteners, but there's now evidence that the company is shifting to tamper-evident screws.
During its teardown of the new MacBook, teardown specialists discovered the tamper-evident Torx screws being used to hold down the hinge screws were filled with some compound that disintegrated when a screwdriver was used to remove them.
It's clear that this compound was added after the fasteners were tightened down, suggesting that Apple has added a step to the manufacturing process in order to do this.
The image also shows blue threadlocker compound is used on the screws to prevent them coming loose during normal usage.
Why would Apple do this?
My best guess is that these fasteners take a fair load from the hinge, but at the same time are only screwed down into soft aluminum. That leads me to believe that they need to be tightened down - or more accurately, torqued down - with a specific force that's enough to hold them in place but not enough to strip the threads. As such, if a third-party messes with them, and the hinge later becomes loose because the threads have stripped because of improper torquing (which I've come across a lot over the years), Apple will know about it.