This is in your favor if you are trying to sleuth out a cyberbully. Did you know, for example, that just by clicking on someone's website, your computer's IP address is captured? This is a series of numbers that uniquely identifies your computer. A website owner can "see" some identifiable information just from looking up your IP address. Try it yourself. By using a technique called reverse lookup, you can find out information on your own Internet Service Provider (which includes what state you live in.) However, it's not that easy for an individual to find out your identity through this IP address, because privacy laws prevent Internet Service Providers giving out user information to just anyone.
Some of the links below will help you in your search to sleuth out an anonymous cyberbully.
How To Trace An Anonymous Email Address
How To Find Out Who Owns A Website
How To Get Someone's Computer's (IP) Address, then use The Reverse Lookup Tool.
How To Trace An Anonymous Cell Phone Number
As always, in providing this information, our intent is to help the targets of cyberbullying regain some power in combating their situations. Do not use this information to reverse cyberbully.