The same thing happened in Austria when the country was captured by the Nazis. The Masters of the various Vienna lodges were remanded to some of the most notorious concentration camps, including the Dachau in Bavaria. Then it happened in Czechoslovakia, then Poland . . . Holland . . . Belgium . . . Norway . . . In Spain, General Franco in 1940, sentenced all Freemasons to ten years in prison as soon as they were identified as members of the craft. When France fell to the Nazi's, the Vichy government caused the two Masonic bodies of France--the Grand Orient and the Grand Lodge of France--to be dissolved, and all their property was sold at auction to fuel the Nazi war machine.
Those tiny pins are still widely available--now that you know what it means, maybe you should get one in remembrance of a time when your "hobby" might very well have cost you your life. It was not so much a hobby with those in Europe during World War II--it was something worth preserving, even at the risk of their own lives.