The installation source server wasn't properly being checked.

Places that "get it" do checks everyday all the time now a days. CentOS and Debian have built in checking as a part of the distribution to mirrors process. They check against external numbers and checksums.

People are trying to get things all the time. People distributing software to the stupid masses (including most time Windows, part-time linux admins) have to be careful. There is no two ways about it.

On a counter point, its been know since 1995 and 1999 that Microsoft made extremely bad decisions on OS design... What have they done? Effectively nothing. They have built a huge wall around the issues and yet, things get by it time and time and time again.

So... 15 years and 11 years respectively? What say you to that?