Can you track an IP address on a deleted account?

[fatdock549]

Movies often fail to grasp the reality of how the Internet works. Most people have what are called "dynamic IP addresses," which means they change every time they connect to the Internet, so it's not always easy to figure out who was using a certain IP address at a certain time. In extreme cases the police might be able to work with the Internet Service Provider to figure out this information, but it would be too expensive to bother for most cases of cyberbullying.