To enforce your copyright, you have to find out the identity of the infringer. You have to sue them. You have to pony up the money for litigation and in the end, you might just get an injunction (which means they have to stop using your stuff) and no money damages. P.S. If you are a blogger, you probably won't get money damages unless you are making money off of your site. The litigation costs are going to surpass whatever money you recover from damages to your site. Trust. Also, the internet is worldwide. If the infringer lives in another country, that may mean trying to find a forum (court) that has power to compel your infringer to stop and that is willing to hear your dispute.
That little mark that you put on your pictures means nothing if you don't have the means to enforce. It's smarter to use technological protection measures. You can code your pictures so that people can't right click and save or hotlink to your pictures. You can make it so that people can't highlight your text and copy and paste on to their sites. These mechanisms are much more effective and cost-effective in protecting your intellectual property. (I don't know how to do this yet- techno n00b, but if you care that much about your stuff, you should learn.)