Notes

Your IP (Internet Protocol) address is your unique ID on the internet and within it is a location; this tells the servers your computer connects to where you're located (a general location). Anyone in the world can connect to your computer through its IP address. With TeamViewer, anyone can access THAT computer and do a simple command (arp -a) in Windows Powershell [or Terminal if you're using a mac] to find the IP of said computer and all other computers on the network. Using this information, the hacker could exploit the IP to hack into any other computer on the network and any computer that has been connected to the network. A simple search of the history allows the hacker to find information and a simple keylogger install allows them to track your every move. Using the keylogger and/or a password generator, some lucky guessing and/or phone calls, and some code, the hacker would know who you bank through, they'd have complete access to your account, mortgage information, tax records, business statements, etc.

Now we get to the legal stuff: It's illegal to hack, it's illegal to put a keylogger on someone's computer without their information, and it's illegal to trace IPs to a certain point. It's LEGAL to trace an IP to a general area without a warrant, however this doesn't do much other than say "oh this person is in the state/country of X/Y/Z". In order to trace an IP to a physical address, you need the following: A court order/warrant, the IP you're tracing, and the exact time the IP did something to you (ie. initiated a hack). The ISP (Internet Service Provider) is then called and they are required to hand over the information to the police, as stated in the warrant.