I use a nick name, this is not to stop anyone on the Marple Forum knowing who I am, it is to stop other people (e.g. possible employers etc) having an easy time tracking me across the internet with Google.
I may say something this year, that a HR person does not like in 5 years time, I have no control over how Google sorts the results when someone searches for my name, therefore only positive websites that are related on my line of work have my real name.