I love having followers, but when they start showing pictures of naked women on their profile photos... it's time to block those followers...
Log in into Blogger, in your Dashboard, next to everyone of your blogs, you can see the followers your blogs have. Just click on the icon and you'll get to a page where you can manage your followers. Click on the follower you want to block and it'll take you to their profile. There you can block that unwanted follower.