The organisers of a so-called "straight pride" parade in Boston have claimed to be victims of terrorism after receiving envelopes full of glitter.
Three members of Super Happy Fun America called the authorities over envelopes filled with a "granular substance".
The letters prompted a response from the FBI, three fire departments and the bomb squad.
The FBI is investigating but says there is no threat to public safety.
Super Happy Fun America call themselves "an advocacy group for straight rights," though members of the group have been found to have links to far-right and white nationalist groups.
I guess snowflakes are not compatible with glitter.