Tongue Tying

If one of your sources tells you they are pursuing, contemplating, or even having dreams about taking legal action, do not tell the recipient. Ever.

I learned this the hard way; I was covering a conflict between the City of DeWitt and developers attempting to build a subdivision in the area.

Outside City Hall during a council meeting the developers said they were waiting to hear from their lawyers on the best course of action. Their primary 'adversary' as they saw, was City Administrator Brian Vick.
In my interview with Vick following the meeting, I asked him the city's planned recourse if "hypothetically, DTP were to file an injunction."

Vick leaned back in his chair, threw his hands behind his head, and smiled at me; the interview was over.

If your need for a particular source is exhausted on an issue, then it doesn't hurt to bring in questions that can only help. But if you want more information out of someone, don't tell them they've got a lawsuit against them. Once the legal realm is on the table, people don't want to say anything that could get them in trouble, especially something that may be published.

It's not your responsibility to tell someone a lawyer is working against them; they'll find out on their own. Get the information you need before you lock their jaw.