Sandbox etiquette

Can anyone explain to me what the deal is with sandbox etiquette? Or, more accurately, the lack thereof. Some day old started up a conversation with me, by going to my level of the sandbox when others were perfectly open and free (I'm usually at ABC recently, it's nicely tiered with level, so there's a lot of space to not be in someone's way. Also, there are chickens), and then started building next to me. Ok, this is not particularly awful, I understand some people are all about the social aspect, blah blah. But she quickly lost interest in talking to me, and started building massive structures. I'm zoomed in on my shoe because it's got fiddly little bits I'm putting on, and I look up at one point to find out I've been shoved all the way over against the rail by her building. Ok, whatever, not getting in the way of my building. But then, she drops a frigging house on top of the shoe I'm working on. What the hell? What is wrong with you people? Is common courtesy really so alien?

I understand the griefing jerks, they are intentionally trying to be bastards- one dropped an attachment with full mod so I could inpect the scripts before wearing, so I knew it was a push that would shove me across the sim, but then he whinged until I put it on (which I did just to get him to shut up, after getting to a decent stopping point and getting all of my things together)- didn't help that he barely spoke english, so it was just wear _item name_ over and over again spamming my chat channel, not even understanding when I was saying "you know, I know exactly what that's going to do, and I'm not in the mood, I'm in the middle of building right now." At least it beat the other gems I've gotten now and again, that one left after I tried his toy- I've had people sit on my items so I couldn't link them, stupid hovers and proximity pushes, etc. At least it isn't as if I can't take my toys and go somewhere else though, so while I will report them, I don't find them as obnoxious as the people who will just drop a house on me because they aren't paying attention. Sort of funny, isn't it?