Were those users using Debian stable? I use Sid so I usually
dist-upgrade as long it isn't going obviously affect my system, i.e
removing applications I want to keep.
My process on sid is apt-get update && apt-get upgrade && apt-get dist-upgrade
I then check dist-upgrade to make sure nothing critical is being uninstalled. If it is, I abandon that step. The reason I end up doing it this way is that a lot of things like the kernel only seem to be upgraded during the dist-upgrade.