Private chat cyber
Threats have been made that their parent will be told embarrassing things if they don't take part or they will send the images to everyone they know if they do not do it.
This is an offence called "grooming" in the UK and people who have been found guilty of "grooming" have been jailed.
It's against the law in the UK to use the phone system, which includes the internet, to cause alarm or distress. If threats are made against you then it's essential you confide in your parents, or someone you trust so that they can make a complaint to the police.
If you can't print out the threats use the "print screen" button or snipping tool to take a snapshot of the computer screen and then save that somewhere safe.
In our recent national bullying survey, 56% of young people said they have seen others be bullied online and 42% have felt unsafe online.
Or if you have a phone or tablet, use the screenshot function and keep these images safe.
We have had many complaints from young people that new "friends" online have tried to pressure them into taking their clothes off and filming or taking images of themselves.
It is against the law for anyone under the age of 18 to take, send or redistribute pictures of anyone under the age of 18.
CEOP is The Child Exploitation and Online Protection Centre and they investigate cases of sexual abuse and grooming on the internet.