Really??

Do people hack then jack blogs? I have recently seen two blogs that I follow start only talking about garbage that I wouldn't have chosen to follow. One became about stamps (not the rubber, clear, or digi variety) and medals, and just last night a blog in my Reader started displaying only stories about tattoos. When I visited the blogs, there were only these weird new posts. Nothing was there before the nonsense began. Have you all seen this too? And am I just crazy for thinking that a scheme like this would be better suited for a blog with a ton of followers?