A block doesn't need to be completely effective as to prevent violations - all it needs is to provide enough data to authorities so they can make sure you don't do it too often.
This is such a blindspot for ‘24/7 engineer mindset’ people. And, in a professional context, things like this serve as a great litmus test for if someone is capable and geared to look at things at a bigger-picture level instead of just ‘computer problems’.
…not to equate looking at porn with getting burglarised. This is obviously BS.