For 24 hours
Wikipedia is going "off air" in protest at possible US legislation that could radically affect the Internet as we know it. The Internet works because it is free, open and uncensored. This is the way it should remain, even if this sometimes means we can be offended or hurt by what we see or hear. We are adults and can make up our own minds. There are ways to safeguard children which any responsible parent can implement.
This appears on the Wikipedia main page:
"For over a decade, we have spent millions of hours building the largest
encyclopedia in human history. Right now, the U.S. Congress is
considering legislation that could fatally damage the free and open
Internet. For 24 hours, to raise awareness, we are blacking out
Wikipedia. Learn more."