Yes, sure, it leaks some information - but to be fair printing an invoice also leaks information. For me the priority is security. If I get a link (visible or

Yes, sure, it leaks some information - but to be fair printing an invoice also leaks information. For me the priority is security. If I get a link (visible or invisible) that contains a numeric ID, there's the possibility to tweak that link with another number. Ideally, the server treats that number as suspect. Every. Single . Time. In practice I only need one developer to miss the check in one place and I have a serious security issue. Like leaking my entire customer list serious. This has happened multiple times -that we know of-. Yes obscurity is not security. But sequential numbers are insecure by design, and it takes a lot of well-maintained walls to protect them. One crack leaves them very vulnerable.