I think everyone is taking the safety comment to extremes, in the sense that someone would attempt to track you down in this world. Although I think that there are lunatics like that out there, I doubt that Sandhya is getting blank calls because we know her first and last name on the forum. Or that someone else will have a visitor at their door because their name (rare or common) is listed on their profile, along with their location and birthday.
My idea of safety in the virtual world is different. I think that we should not blindly trust someone because they seem "nice". When we give out personal information, it usually means that we have developed some kind of bond or attachment with them, we trust them enough to share those kinds of things. And you really don't want emotions to run high in this world. Once emotions start clouding reality, or rather virtuality, then we lose our sense of direction. And yes, that is also applicable in the real world, but in RL, we usually have others to guide us or smack us and bring us back into reality every once in a while. Usually in the virtual world, everyone is flying solo, leaving behind RL, and finding a place to get away from it all. And God knows there are jerks out there who will take advantage of just that.
So in the end, don't do anything in VL, that you wouldn't do in RL, because it will come and back to haunt you (just like in RL). And use your common sense (preferably in both worlds).