Control there are many kinds. Emotional, physical, mental , and verbal.  Not many people have control over any of these at any time. Sure there are times when loss of certain controls are needed as a release, but only in context. I mean if you work in customer service you do not mock your customers or throw things at them. In that particular kind of case that involves physical, verbal and emotional possibly.  I mean venting and losing some control in some situations is ok but it is just as important to keep ones composure at work in those kinds of situations dealing with problem "customers" you just need to understand that keeping your self in check is important in certain situations.