Bobek90: We can? Then I think we are talking about a problem that doesn´t exist, everyone who doesn´t want to show information about country where he lives right now set "others" and problem solved.
Hovewer, I want to disagree with you. The information about the country where you live doesn´t is a very private matter for me, more curiosity. Somethin truly private regarding your location, would be the concrete city or the community where you actually live. Instead what say me Germany or United States? It can mean point A, or point B, tens, hundrend or thausend of kilometers far away point A.
We are living in a time where there is less and less privacy. Our searches on the internet aren´t private, state agencies, large multinationals such as Google, have access to them 24 hours a day. Really in this context, country where you live, is it a sensitiva personal information? Guy is from Czech Republic. What that information tells me respect him? He can life anywhere around this country. I don´t even know if he is local, he can be a foreigner. And he is one of the 10 million people who live there. So... tells me not much.

TentacleMayor: To a stranger yes, the country alone isn't very useful in identifying you. To someone who knows more about your preferences, the time of day you're active on GOG, your writing style etc. it can be used to link your online persona to meatspace. So if,e.g. friends, family or classmates go snooping around to find your post history on the place where they know you buy your games, you don't want to narrow down their search by giving away the country. Assuming of course they don't know your username and you want to keep it to yourself.
Don´t get me wrong, I don´t want to offend you in any way, but the example you have given to me seem so surreal. That is, first to think that a friend of yours who know your routines on GOG, preferences, and so on - although I don´t understand how someone can know all this about you and didn´t know a simple nickname - dedicate his time to analize writing style of tens of user to find out the nickname that his friend has in GOG. It doesn´t make sense to me. It´s just not that simple, we all like to think we are unique, but we don´t. It´s very difficult to do what you suggest, you aren´t the only one who might have that preferences, be from that country, and use that language style. It´s not so easy.
But most important, for what all this? What you hidding from your friends or family here? Don´t you want they to know what games you play? But you said they already know you preferences... Don´t you want they know what you write on GOG forum? But´s it just all about games, just a hobby, I understand if it were forum about, i don´t know, politics preferences or mental illnes, I mean somethin a lot more personal. I don´t get it, do youy have the same nickname here and in dirty sites like ...hub? Well, yeah, you shouldn´t, but don´t worry, if they say they don´t watching that stuff, they just lying.
Ok, now seriously, I don´t see sense in the example that you gave, and most importantly, it remains something unprovable for me. Also, if a friend or family member or classmates would searches for my nickname on GOG, has had interest in knowing all my routines and preferences, even language style I use, then the information about country I live in from my GOG profile would be the least of my problems, trust me.