Earlier quoted context omitted.
When would that be the case? When you have another job on the side? How is that your employer's business?
Personally, (I'm less than 25) I make about 75% of my income from the company I work at, the other 25% doing odd jobs, websites, etc. That latter percentage is probably increasing every month too. I can't imagine the company I work at being super excited I'm (for example) doing code reviews; or running a website. Technically, I don't have a clause in my contract forbidding me from doing external work, so long as I gi…
There are plenty of scenarios in which an employer believes that they deserve to know how their employee conducts themselves outside of work, including other jobs, and in those scenarios, this should be specified in the contract. In the news business, working for someone who might intersect with your beat, e.g. making phone calls for the local chapter of Democrats if you're covering politics, will often result in a severe reprimand if not firing. If you want to be a schoolteacher, you can be fired for having worked in porn, even if those days are over. [0]
[0] http://www.cbsnews.com/news/stacie-halas-fired-calif-teacher...