I know a fair number of people who blog - whether regularly or sporadically, for work or personal interests, out of a sense of obligation or because of some urge to purge.  Whatever their motivation, the net result is the same - a piece of themselves suddenly available for pretty much anyone to look at.

Or steal.

If you write for fun or profit online, you need to be aware that a lot of other folks are more than happy to borrow your ideas.  And your words.  And claim them as their own.  In academic circles, we call this plagiarism.  Personally, I like to refer to it as craptacular.  

This article is a good summary of some ways to determine if someone else is stealing your content. 

I've personally caught students cheating by using the Google method this author notes.  It works amazingly well so long as you choose a unique enough passage.  So enjoy writing.  Enjoy publishing.  And remain aware that someone might be passing off your inspiration as their own.