The profile links are basically just URLs with the ID substituted in. Example as follows.
Facebook
Code:
https://www.facebook.com/app_scoped_user_id/[fb_userid]
Twitter
Code:
https://twitter.com/intent/user?user_id=[twitter_userid]
Google
Code:
https://plus.google.com/[google_userid]
LinkedIn
Code:
https://www.linkedin.com/profile/view?id=[linkedin_userid]
Not all the providers have a profile URL that's usable from ID though. Using IF substitutions you can condition them to show only when the id exists. Example as follows.
Code:
[cb:if fb_userid!=""]https://www.facebook.com/app_scoped_user_id/[fb_userid][/cb:if]