Always being a security conscious professional I lock my machine all the time, Yep I haven’t in the past ( and learn’t from that) as no one wants to email the infrastructure team proclaim you love them or ask one of them out for a drink and bcc in the rest of the team.
In lots of places it seems fair game if you don’t lock your machine, we’ll one thing you can do to seek revenge, especially in environments that people have access to other’s machines through an UNC path is to have a play with the SQL splash screen
This might be familiar what appears when you start Management Studio ( this one obviously is sql2014 ( other versions are available)
This is basically a bmp file called ssms.splash.bmp which lives somewhere in the SQL install path such as
C:\Program Files (x86)\Microsoft SQL Server\120\Tools\Binn\ManagementStudio\ssms.splash.bmp
Which you can update for people who annoy you 😉
Or this one, if you really wanted you could change it daily and watch people panic, or switch it back over when they report it to the helpdesk
And the one for the united fans out there ( or really the Liverpool ones) which I have as my current splash screen
or you could even go retro!