Tomorrow this blog will go dark to protest against the Stop Online Piracy Act, generally known by its initials as SOPA. In case you haven't heard, this is a nasty piece of legislation that the United States are planning to pass to make it easy for anyone to take down someone else's website if they claim copyright violation.
It doesn't have to be the person who's complaining that their copyright has been violated, and there is no need for a trial: the website will be taken down before any case is heard. You will be held to be guilty until proved innocent - which is going to be bloody hard in the case of copyright law.
It's very easy to inadvertently violate copyright. Indeed, some of the people behind the new law have been found doing just that. We're all at risk of being taken down and so are all of our favourite websites.
If you want to protest, you can find the code to make your blog go dark here: http://sopablackout.org/
You can find out more about SOPA on Wikipedia here: http://en.wikipedia.org/wiki/Wikipedia:SOPA_initiative/Take_action
Edited to Add: to black out your website, open the template for your blog. In Blogger, you go to Design, Edit HTML. I recommend clicking on Download Full Template first: this will allow you to save a version of your blog on your computer.
It helps to leave a space before and after the code, so you can find it easily when you want to delete it. Save the template and check your blog. It should now have gone dark!