A Google Webmaster Help thread has about 60 posts from searchers and webmasters asking Google to join the SOPA protest by blacking out the Google search home page.

One searcher said:

It is a calculated risk. How much money can Google lose by doing this on a single day vs how much Google can lose if SOPA is implemented?

What I expect Google to do is darken their logo and place a link under the logo for users to learn more about the downsides of SOPA. I do not expect them to do a complete blackout of their site like others.

But should they?

Forum discussion at Google Webmaster Help.