There may also be a (very weak) reason around bounds checking and avoiding buffer overflows. By rejecting anything longer that 20 characters, the developer can be sure that there will be nothing longer sent to the back end code. While they should still be doing bounds checking in the rest of the code, if the team making the UI is not the same as the team making the back end code, the UI team may see it as a reasonable restriction to prevent a screw up, further down the stack, from being exploited. Again, it’s a very weak argument, but I can see such an argument being made in a large organization with lots of teams who don’t talk to each other. Or worse yet, different contractors standing up the front end and back end.
Another Cybersec worker here, and I’ll broadly agree with all this. That said, I’d also point out that, depending on your site setup, the browser history may be nothing more than another place to correlate information we have from elsewhere.
Several sites I have been at have used Data Loss Prevention (DLP) software which automagically records (and possibly blocks) data moving into and out of the environment. This can be very detailed, to the point of knowing when someone copy/pastes data to a web form. I’ve also been at sites which sniff web traffic at the firewall and record full pcaps and extract metadata for quick analysis. So yes, for those not aware, deleting browser history or using “in private” browsing or other steps to avoid us seeing your porn browsing, may not be as effective as you think.
All that said, I’ve never been on a Cybersec team which has had enough time to really care about porn browsing, so long as you are not putting the network at risk. And, so long as HR/Management doesn’t tell us to care. We have better things to spend our time on.
Lastly, if you don’t want us seeing it, don’t so it on a work computer. Look, we have lots of ways to see what you are doing. Just, do that stuff at home, on your own hardware. And leave the work computer for work. Writing up misuse reports is something I really hate doing.
But they pinky promised that only the “good guys” would use the “front doors”. /s