Some threats and risks that could happen when using a IT communication website could be the system crashing causing you to lose all work and having to start again.also, your computer might get infected with a virus that an effect all the work on the computer.
When using a social network, you will come aross fake accounts. a fake account is people pretending to be someone there not but can also still cyber bully, or if they get ahold of your real details they could come to your house or harrass you using a phone. This is why it could be dangerous if you put up all your details, instead just put up simple things nothing too personal, also there is a problem in copy right, someone could copy what you have said/wrote and pass it off as if it was theirs.