When looking at P2P systems it is important to understand their classifications. They are as follows:
- file sharing
- processor sharing
- instant messaging
All three have their own set of dangers. Many of these dangers are caused by the design and structure of P2P systems. Some of them are designed to bypass firewalls, for instance. Firewalls are the front-line defense for computers, yet P2P protocols are made to get past this form of protection. This creates a real security risk for users.
Those that are going to download files through a P2P system cannot rely on their firewall to block the dangers that may lurk within those downloaded files. This places the burden on the user to configure their own computers for some level of protection.
Then, added to the threat of security, is the leak of personal and sensitive information. It is particularly a risk for users who open their entire hard drive for sharing, whether willfully or unwittingly.
On top of these hazards, there is the risk of computer infection. This can materialize in something like a P2P worm that masks itself so that the downloader is, naturally, unaware of its existence, and simply copies it into his or her file-sharing directory ready to pass on to others.