If you have an iPhone, you need to take note of this.

A number of men on the New York Subway have started sending pictures of their penises to people whose AirDrop settings are not set to private.

Speaking to the New York Post, 28-year-old Britta Carlson became a victim of this new (and somewhat disgusting) trend.

She told the publication that she had received a message via AirDrop entitled ‘straw’ which was sent anonymously. It turned out to be a “huge close-up picture of a disgusting penis.”

There are three receiving options on AirDrop, which is only available on iPhone: a user can either set their phone to be able to receive files from everyone, just their contacts or no one.

People are leaving their AirDrop on and have the setting set to ‘everyone’. For AirDrop to work, you need to be within approximately 100m of a person.

The function was originally introduced to allow users to easily exchange files and documents without using any of their data.

However, making sure that you don’t end up getting a weird picture via AirDrop is quite simple.

Where it says AirDrop receiving (providing you even have it turned on) click the button and you will be given the option to receive content from no one, your contacts or everyone, and then click on the desired option.