Last month, a letter that encouraged people to "Punish a Muslim" on 3 April started to appear across the UK. The letter was also sent to Muslim MPs.
According to police the threats have spread to the US. A "Punish a Muslim" letter was sent to a resident in Takoma Park, Maryland.
Viral messages on WhatsApp have been asking Muslims to remain vigilant or even stay indoors.
Jamilla Hekmoun, a 24-year-old researcher, and Umar, a 22-year-old student from London, saw the letter spreading on social media and decided to create the hashtag #ProtectAMuslimDay.
The initiative works by people calling the numbers on the flyer if they want someone to walk with them or someone to stay on the phone with them.
After they call the number, the organisers will contact one of the volunteers that will have signed up on a Google doc. So far they have over 100 volunteers.
People love the initiative.
And are spreading the word.
The Met Police say they have received "no credible information" to suggest that hate crimes will be committed on 3 April. They said an investigation is being lead by Counter Terrorism Policing North East, supported by the Metropolitan Police Counter Terrorism Command, to find those responsible for the letter.