Last year, I wrote a tutorial about using ‘Proxy in Firefox‘ on my old blog. Today I was doing a bit research on same topic (Yes I am planning to write another informative tutorial on the same topic).
While googling the things out, I found an excat copy of my old post on a blog hosted on wordpress.com. That blogpost was a complete ripoff of my original post. Even screenshots used in that posts were hotlinked from my blogger account. No attribution or linkback was provided to my blog or blogpost.

Without a delay,  I contacted the wordpress.com support and opened a thread in their support forum.

[See Thread Here]

And I was surprised to see official responses rolling in in couple of minutes. The forum moderator Bubel responded in my thread, and with in 15 minutes, I got an email from wordpress support team stating that duplicate post is removed from that wordpress.com hosted blog.
Seems like WordPress.com takes plagiarism very seriously.

I appreciate their support and quick response.

Note: If you have any such issue with blogs hosted on wordpress.com, please notify them using the procedure mentioned here.
Another good read in this regard is: How to Deal with Online Plagiarism at DI.