I don't have a side on my case either. Mine is missing mostly because I seem to have misplaced it. Had a month or two where I had the side off because my computer was overheating with it on and the only way that I could keep it cool was to have a 12' floor fan blowing on it with the side off. After that I had a virus but didn't know what it was and thought it was actually a hardware problem so I was continually swapping out hardware for awhile hoping that something would work.
My computer room ended up being cleaned at some point and now I can't find the side of the case. Atleast I don't have to worry about screwing up the airflow as my case has no fans beyond those on the CPU, GPU and the PS.
Now where did I put that camera...