During the turn of the century an epidemic was sweeping the country. Newspapers everywhere were reporting similar instances where “mashers” (period slang for predatory men) were getting stabbed with hatpins. This became so frequent that this phenomenon was given the name “Hatpin Panic” or “Hatpin Peril”
Hatpins could be up to a foot long and were used by women to secure their elaborate hats to their hair. The suffragette movement at the time was allowing more women to be independent and travel freely. It also encouraged girls to fight back and speak up about harassment.
Image from the San Francisco Sunday Call, 1904
Eventually hatpins became a real threat to not just men but women as well. For example one woman thought she was just being playful, but accidentally stabbed her boyfriend in the heart, killing him. In another instance a woman and her husband’s mistress drew hatpins as if they were swords. To combat this, regulations started to get put into place regarding the length of hatpins. In Chicago an ordnance was passed banning hatpins over 9 inches in length. However, most women would rather go to jail than let mashers get away with harassment.
By the end of World War I, Hatpin Panic was soon overshadowed by another “social menace”, the flapper.
Source:
Fashion and Protest in America 