From a colourful butterfly and an oddly-shaped spiral to a pink layered heart, they could be the scrawls of young children.
But these symbols are actually used by paedophiles to identify their sexual preferences to other predators on social media.
The innocent-looking logos 'distinguish' what gender and age of child the paedophiles are sexually attracted to, according to experts .
Seen on blogs and webcasts, they are accompanied by disturbing descriptions such as 'BoyLover', 'GirlLover' and 'LittleBoyLover'.
And the symbols aren't just limited to social media - with paedophiles having etched them into rings and pendants and even imprinted them on coins.
They have also been previously found on children's toys - to the horror of parents.
The logos - and their sickening meanings - were detailed in an FBI bulletin, titled: "Symbols and Logos Used by Pedophiles to Identify Sexual Preferences."
Read more:
The document was sent to police forces across the U.S. and later published on Wikileaks , although the Mirror Online is unable to confirm the authenticity of it.
So, what does each symbol mean? Scroll down to find out.
This logo, featuring a blue spiral-shaped triangle surrounded by a larger triangle, is used by paedophiles who like young boys.
The small triangle represents a small boy, while the bigger one represents an adult man, according to the FBI document.
This is a variation of the BoyLover logo - used by paedophiles who like very young boys.
It also features a spiral-shaped triangle, but its corners are not straight.
This is deliberate and is meant to resemble the scribbling of a young child, FBI agents say.
This logo, featuring a small heart surrounded by a larger heart, signifies that a paedophile is sexually attracted to young girls.
The two hearts 'symbolizes a relationship between an adult male or female and minor girl', according to the U.S. agency.
This logo is used by paedophiles who do not have a gender preference.
These people are sexually attracted to young boys and girls.
This symbol is used on social media by paedophiles. It tells other predators that they are interested in children.
The FBI bulletin describes how paedophiles are using logos like this one to 'promote their cause'.
"Pedophile activists advocate for the social acceptance of sexual relationships between adults and children," it states.
"These organizations seek to decriminalize sexual relationships between adults and children and to legalize child pornography based on their belief that children have the ability to consent to sexual acts."
ncG1vNJzZmivp6x7pa3IpbCrnZOkv6V6wqhlrqNfo7K4v46uomavn6e5pXnNnq6sZ6CWv6a606xksJmio7Klec6vnKtlmaO7sK%2FEp6tmpJ%2BkuKq6xmZucWxjaoZ4