- Someone may enter into the computer room. He may take away all storage devices on which sensitive data is stored.
- An unauthorized user may take access to personal data of someone. He may then use it to again some advantage. For example, if someone gets access to your credit card number and Pin Code, then he can use it for online shopping from your account.
- An unauthorized user may use an online mail server, like "mail.yahoo.com". He may view e-mail messages of other users.
- Some one can send a virus program into a network. This virus may slow down the network and may corrupt important data on the network server or data of other computers connected to the network.
- Some user may gain unauthorized access to bank accounts. He can transfer a large amount of money from other accounts to his personal account.
- A person may make a computer so busy by sending many requests, so that the computer becomes unavailable to authorized users. This is called denial of service situation.