Yoko Ono -- who was widowed 33 years ago when Mark David Chapman fatally shot  John Lennon -- posted a photo of John's bloodied glasses on Twitter. The caption reads, "Over 1,057,000 people have been killed by guns in the U.S.A. since John Lennon was shot and killed on December 8th, 1980."

She also tweeted a number of messages, including, "The death of a loved one is a hollowing experience. After 33 years our son Sean and I still miss him," and "31,537 people are killed by guns in the USA every year. We are turning this beautiful country into a war zone."