This is was known as a "svastika." It was a Sanskrit symbol meaning "peace" and "good-fortune," used primarily in Indian ideologies, but has since been seen differently. It is now known as a "swastika." A swastika on a red flag with a white circle behind it is the swastika most people know of today, because of Hitler's famous Holocaust. If shown to a person who believes in Judaism, they may take offense when seeing it, as the Holocaust involved Hitler's failed purge of the Jews. However, it is becoming more popular as a joke, rather than an offensive symbol, these days.