I think mine is fairly obvious.  I initially set up an account using my initials and realised that didn't serve the purpose very well if I wanted to get more involved so I set up an account as In Wales.  

I suppose I see my perspective on European and political issues being largely shaped by my experience of living in Wales so it was the key aspect of my identity that tells people who I am in this context.

I think online I am on a far more equal footing than offline.  This method of communication is the easiest for me and people judge you by what you write (and how you write perhaps).  Online, my contribution is as valid and worthwhile as the next person, which is far from the case irl.  I'm the same person online but with fewer obstacles in my way.