Step 2 – Make sure your all other tabs in browser and other services in computer are closed. If Possible for you then delete all the cookies-cache and browsing history from your browser.
Step 3 – While chatting on Facebook go to Start >- Run >- cmd .
Step 4 – After Opening command Prompt Type netstat -an command and hit Enter.
Step 5 – Now you will get Ip Address of all the established connections there .
Step 6 – Note all the suspicious Ip’s and trace user using ip address tracer sites like whatismyip or ipmango.com .
Thats It !
You can use same trick for tracing ip of someone’s on Skype, gtalk and Yahoo Messenger .