Disadvantages

Some unauthorised people may get access to information that you want to keep private such as you name, age, gender etc.
Harrasment from people that you do not know can sometimes be a case when using social networking sites therefore you should only speak to people that you know on social networking sites to help prevent this.
Social networking sites can sell your private information to anyone who wants to buy it.
Some people fake their identity and pretend to be someone else therefore, users should be very careful who they speak to on social networking sites
If you are unsure of how to use some social networking sites it can be very time consuming,
You have to constantly monitor your social networking site and its content which could also be time consuming.
People that are using social networks are becoming victims of scams
Users have to be very careful when using social networking sites in order to stay safe and secure.
Some people fake the identity on social networking sites
Social networking sites such as Facebook can become very distracting when you are trying to carry out other work on the internet.