The bitcoin protocol does not require people to identify themselves in order to transact though some businesses may need to for compliances reasons. Unlike a bank where people often have one or two accounts, you can create as many bitcoin wallets as you like.
It can be dangerous ı mean that untraceable. This feature of Bitcoin of also attracts crime. People can buy and sell drugs and other illegal items with significantly less risk of being traced by authorities. Bitcoins in this regard are similar to regular cash which is used by criminals. This fact may bring unwanted attention from governments that will outlaw Bitcoin.