Personal Space
I stumble upon an article line, which is kinda true for many (me included 
)
Personal space is the region surrounding a person which they regard as psychologically theirs. Most people value their personal space and feel discomfort, anger, or anxiety when their personal space is encroached.[1] Permitting a person to enter personal space and entering somebody else’s personal space are indicators of perception of the relationship between the people. There is an intimate zone reserved for lovers, children and close family members. Source; Wiki
But this time, I am going to elaborate more on “personal space online”, I mean most of our interactions in this time and age are online or in the web. So the technicalities of these topic is somehow broad but very familiar in some way or another. Having a personal space online is really different from the actual or the physical space which is already categorize in the above image.
The interesting fact (based on the image) is that Social space is just outside the personal space which is kinda far for some especially when we relate it to personal online space. Physically, the distance is similar to intimate for personal space even others publicly can access a closer zone. So social media has really affect the way we see people or how we interact with them. For example, We have the tendency to be intimate with online friends even though you just met or even strangers.
In the personal space, you can relate it first as social space, but it the social media network, the space is closer than you think (psychologically). That is why many are getting intimate online even they barely know the person, in terms on how they treated everyone online especially with their Facebook friends
Each of our Facebook friends can also be divided according to how close or what relationship they have with others. I bet many group them into one space category which is really common for all but some really have a way to group them to avoid unwanted viewers (or worst stalkers). The advantage is that we can keep track of people especially our close families and friends but what about those who we just met or just hang outwhich we have given them access to our personal space online (except when you set privacy controls in your social networking settings).
This is also why I sometimes (really sometimes) get irritated when some suddenly enters and intrude my personal space for that manner, though each of us have a different personal space range, maybe some has a very wide social space (especially online) and also has its own rules when it comes to personal space and privacy. Knowing a person is very important on how you can measure or test how we see our own personal space both physically , psychologically and online space. Just remember the limits. cheers 
