One of the things that's written into various computer laws is that unauthorized access of a computer system with another's credentials is a crime. That's been drilled into me at various organizations where no one was supposed to share any credentials. That is something many sysadmins drill into users, while sharing their own system level credentials for accounts like root, sa, system, and more. I've seen no shortage of these accounts in use across multiple services or multiple people from those that would admonish a manager for sharing their password with an assistant.
This week Troy Hunt wrote about politicians sharing passwords, and the problems with doing so. It's an interesting read, and certainly points out that the expediency of having users share a workload has plenty of downsides in accountability and auditing of actions. I think there's little excuse for sharing security credentials in UK government as there are other solutions to handle this issue. I am more sympathetic in real time environments, like hospitals, where the login process might literally cause a death in the event of a delay.
Leaving aside the authentication aspect, we often share data among individuals inside of an organization. In fact, outside of sysadmins, there might not be many people that really understand who should have access, let alone who has access, to some data. In fact, over time it seems that most organizations tend to lean towards allowing an ever-growing number of people to access data in file shares. While we might prevent database access and grant/revoke this at times, the output from our systems often ends up in Excel sheets or other files and people that might not have direct access still see the data.
The real physical world is just as bad, since many people may leave data lying around on desks or tacked to a wall. Just like credentials on a post-it, we have lots of data available for others to read, though physical access is required. However, have you thought about how many people have physical access? It's not just your co-workers, but also janitorial staff, tradespeople, and others likely wander regularly through your office spaces.
Security is a tough battle, one that is interesting in that most of the time we don't need much more than good passwords. Most people don't have the time or inclination to deal with their own data, much less yours. However, when an attack is targeted on your organization, from outside or within, it's extremely difficult to ensure data won't get lost.
I don't have a great solution, but I do think that there are good reasons to limit access to data on our systems, not the least of which is auditing and accountability. Beyond that, however, we have to hope that our users have some judgment about with whom they may share reports and other data.