User blog comment:SallyPerson/NO LONGER BANNED!!!!!!!/@comment-1897744-20100414235258

http://en.wikipedia.org/wiki/IP_address

It's like you're internet finger print. The number is shared between a network of computers all linked together, basically: so, if you posted something from school, and then someone else posted something from a different computer that was still on your school's network, they would have the same IP address.