Google Webmaster Tools 500 error on others people blogs

Hello,

I have taken over a blog that was set up by a previous web designer. The existing blog was broken so I deleted everything and re-installed the whole blog. Everything seems to be working fine. However, in my google webmaster tools I am getting a whole bunch of 500 errors. Most of these are other peoples blogs?? Did the previous designer have something set up that was pulling blogs from other sources? If so, how do i correct this?