Spam on my blog?

What is up with foriegners posting comments on personal blogs in a language that I can't understand? Does this happen to everyone or just me? I just got a comment from a stranger named Rodrigo on my previous post. I quickly deleted it, and feel somewhat unsettled about it. But since I'm new to the blog world, maybe this happens all the time and I'm just now seeing it. But common or not, I think I hate it.