I worked at a top US law firm as a corporate lawyer for almost 10 years (my first career). I'd say the brain starts to experience life in 6 minute increments. I think you'd need to accurately capture all the moments when an associate is in front of your computer but not working for this to work. I suppose your plan B would be to sell this to firm management as a timekeeping audit tool. it could be a valuable informative tool that they don't initially rely on but can use to test accuracy etc before they move on to actually using it.