Although the police can get information from your computer's hard drive, it is helpful if you don't delete anything until the police have decided whether they need it as evidence.
There are quite a few instant messaging apps including Snapchat, Whats App, Secret, Whisper and Instagram.
Anyone who makes threats to you on the internet could be committing a criminal offence.
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.
CEOP is The Child Exploitation and Online Protection Centre and they investigate cases of sexual abuse and grooming on the internet.
From what we have heard from people who have been bullied online, the most vicious gossip and rumours are often spread by people who were once your best friends so it's best to keep secrets and personal information to yourself.
Impersonation – This is when someone will hack into someone’s email or social networking account and use the person's online identity to send or post vicious or embarrassing material to/about others.
The making up of fake profiles on social network sites, apps and online are common place and it can be really difficult to get them closed down.
This is an offence called "grooming" in the UK and people who have been found guilty of "grooming" have been jailed.
Remember: everyone you meet on the internet is a stranger and you need to keep personal things personal to you, don't share your secrets with other people and if anyone asks you to do anything that makes you feel uncomfortable then don't do it.