A conversation yesterday with someone whose employer blocks access to Facebook and other sites on the social web highlights a real conundrum with such bans, as Scott Adams perceptively illustrates in yesterday’s Dilbert comic strip. Many employers cite time-wasting as a prime reason for such bans. Some worry about security risks and the threat of bringing in viruses into the corporate environment. Yet Alice in the Dilbert strip spotlights a flip side to such bans when she thinks about what…