Journalists use linked in information for criminal investigation pieces

(as published in Huffington Post - http://www.huffingtonpost.ca/stephen-weir/linkedin-privacy_b_1401066.html ) 

Stephen Weir

LinkedIn Privacy Alert - Telephone, Telegraph and Tell a Publicist

LinkedIn With Investigative Journalists - Maybe You Want To Drop Me Soon

Yesterday, for the second time in a month an investigative criminal reporter has called me looking for info on people that I am linked into through the popular business social network.
This time it was concerning a case of medical fraud, and one of my Linkedin  contacts was related to a doctor arrested in the US. 
The Star was trying to reach Toronto relatives for comment. My Linkedin contact, a member of the media himself, was related directly to this doctor.
At the beginning of the month the Globe and Mail was asking for Linkedin information that would help the paper contact a woman about to be charged over an insider trading issue (gold stocks).
Their calls kicked off an internal ethical debate.  You see, I am a trained journalist, I live to write about diving, the ocean and anything we swim in. But, freelance writing journalism, being  one of the lowest paying jobs on the planet,  requires non-writing support to keep the car payments on sched.  So,  I am also a very active publicist with contacts in many different communities around the world. I work in the arts, in the Caribbean community, in our country's publishing industry and even the world of the wrongly convicted. 
One side of me wants to help out any reporter looking for assistance in any  legal way possible. The other side of me is wondering if my Linkedin connection information is subject to privacy concerns, and I should not willing give out numbers, email addresses and job information.
Background: I was quick to jump on the Linkedin bandwagon. In the early days almost everyone I approached to link agreed to sign up with me. As a result I have two accounts, one with over 1,500 connections, the other with 600 or so.  According to Linkedin I have over 9 million colleagues in terms of  first, second and third level signees.
It works both ways. Lately I have been getting Linkedin requests from real estate agents from Atlanta, investment accountants from New York and even IR experts working in Nigeria.  I weed out the insurance agents, sex trade workers and tax specialist, but,  link with almost everyone else.
So, in reality the vast majority of people on my two network are unknown to me. Do I owe these vast group of strangers some sort of privacy protection? People who become my contacts decide themselves as to what information they are going to give me, so,  should I consider their data as being public information?
Giving private information to a publicist is not like talking to a reporter off-the-record. As a journalist your secret is safe with me.  As a publicist? You must be kidding.  It would be hard to convince the police or the courts that a public relations person could "protect his sources".
In reality a publicist will sing loud, long and probably pay for the drinks (receipt please).  The world used to say the three best ways to get information out - telephone, telegraph and tell a publicist.
Question: So what did I do?  In the first case, I was actually once removed from the person being investigated for exchange irregularities.  I had no idea who she was.  I was Linkedin to this woman through a connection with the Wine Ladies radio show. Believe we were all involved in a community  fundraiser. I told the Globe the connection and left it at that.
In the case of the doctor arrested in the US, I did phone my Linkedin in contact ( I have him in my own data base ) and asked if it was alright to provide the Star with his number. He said yes. I did. They talked. Then the Star called again wanting contact information on other family members.
Given the size and scope of my data base, what will I do the next time I get a  media call? Don't know. Depends on how moral I am feeling at the time.
I have an eclectic life. I used to believe in that philosophy that says you are the sum of the five people you most hang-out with. Nowadays does that apply to Linked In friends as well? If so, maybe I should purge? Or more importantly, should you the reader, review your on-line data and flush me out of your maililng list? ( I wouldn't blame you).