Google Talk Friends List Getting Out of Hand? Try Bankruptcy

If you exchange a couple of email messages with another GMail user, Google Talk assumes that the person at the other end is a known contact and will automatically add him (or her) to your friends list.
[Sometime back, I had a conversation over GMail with someone who plagiarized content and the person showed up in Google Talk Friends list the very next morning, courtesy Google.]
Yes, there’s a software setting (both in GMail and GTalk) to prevent Google from adding complete strangers to your friends list without permission but that’s not default - so before you discover the setting, you may already have created a long and unmanageable list of virtual friends with Google Talk.

If you are also troubled by this “friend overload” problem, try the bankruptcy route - that means remove all existing friends from Google Talk in one go and make a fresh start.
You can either manually remove Google Talk friends by right-clicking each of the names or use the help of GMail. Here’s how you can do the clean up:
Step 1: Export all your existing GMail contacts to a CSV file. [Contacts -> Export -> CSV]
Step 2: Goto GMail Contacts again, click the “All Contacts” tab and scroll to bottom of the screen. Do a “Select All” and click “Delete” - this will also wipe off all your current friends from Google Talk.

Step 3: Now just import the original contact CSV file back into GMail so you don’t lose any of the email contacts. [Contact -> Import -> CSV]
None of your GMail contacts would show up as friends in Google Talk now. You can now selectively add friends to Google Talk. Click the Add button in Google Talk and tick the GMail contacts whom you would love to see in your Google Talk as well.