Let's also consider an employer's perspective here. OK, you are a Y Combinator start-up, and you have hired your 18th employee (there are at least 10 that have 20+ employees, I think). If that employee were doing something like this on the side, would that sit well with you? How would you draw the line?
Forget the ownership aspects of whatever the employee is creating on the side. Would you be happy as his/her manager to realize his/her mental efforts are going somewhere else?
