Many years ago, we had an ISDN connection at the office, and a bank of modems. HTTP connections were forced to go through a Squid proxy. I had a similar little script which grepped the log for "interesting" keywords, but not much interest was shown in this from above.
However, one day all our sales people and managers were gathered together at a hotel for a big meeting. One of my colleagues in network admin was due to address them, and took the opportunity to remind them that, as in the T's and C's they had acknowledged, our network was monitored for inappropriate (and expensive: on-demand ISDN had a per-call cost) usage. There were no sackings as a result, just a few red faces as he stood at the lectern and read out a few of the less unsafe-for-work domains that had been visited the previous night.