I submitted this as a lightning talk before realising the security devroom might be more appropriate. The Bastard Operator From Hell enjoys abusing his users. SystemTap allows for very easy dynamic code injection system-wide (kernel, libraries, applications). This talk gives a brief overview of what is SystemTap and its capabilities. We then demonstrate how it can be used to dynamically insert questionable code at any level to spy on users and modify behaviours of applications and system components very easily. This is not about novel techniques or breaking trust boundaries (we assume you are root already). This is only about making things easier for both the good and the bad guys. This is a 20 minutes talk (say 30 minutes with pleny of time for questions). About me: I enjoy playing with Unix systems, breaking things, fixing things, reading code and tinkering with low level components and tools (kernel, libc, debuggers,...). I have been using SystemTap a lot in the last few years and started to see it as the ultimate hammer. If you measure Open Source activity by amount of code written, I haven't contributed in any significant way to any project. I wrote small patches to fix or improve tools I use like arping, strace or SystemTap. I co-founded the Free Software Users Group Arlon (Belgium) where technical talks and social meetings are organised frequently. I am currently unemployed and using my free time to toy with ideas like the one described in this talk.