Sometimes it IS necessary to cut right through a floor joist to get a toilet in just the right spot. This frequently happens in remodeled older homes. The problem here is that it was not re-supported afterwards with the proper floor framing (using headers and trimmers). Because of this, the toilet in the bathroom above is very loose - and yes, it was already leaking!
We were told that a licensed electrician completely rewired this 80-year-old home. New wiring and lots of holes were drilled through floor framing in the basement. A licensed electrician should know enough to not drill multiple holes through floor framing to install cables.
Our guess is this electrician was not licensed. If this is what we saw in the basement do you wonder if there were other electrical problems in the dwelling? If you said yes, you would be right! This is not only a structural problem - bad wiring can cause serious injury and fires!