It is not uncommon for companies to allow exceptions. If you use a company computer during lunch, or say take a short break I believe it is acceptable. Depending on company policy. I have been with companies that put computers in their lunch room for employee use to conduct personal business during breaks, I thought that was a great idea.

We all have our views on this. Those that oppose ***-for-tat in you giving your opinion on dedicating so much time to the company that it's difficult to take care of personal business has their head in the sand. This is a very common practice among employees as well as management.

It is the companies policy ultimately that governs the privilege, but I believe that most companies are sensitive to their employee's needs, and work around protecting their data.