How much trouble can he be in?

Im not sure what your company policy is on this, but at most jobs, it is intolerable. Usually, if they've never been in trouble, they will be. But if they are having any problems then they may suspend or fire him. If nothing is done, try calling his house at all hours of the night.

I completely understand the MILD ethical breach here by providing private information like a phone number, however, try and keep the issue down to earth. The fact is that for a small amount of money, anybody could get a personal phone number very easily - and we know they already have your name. The people who go out of their way to obtain personal information by paying for it are likely determined to do you harm. This is not the case, correct? So let's breathe calmly about that scenario!

The issue that has you "furious" is...that someone at work didn't ask you, took the liberty themselves, invaded your privacy...? I'm guessing that the FEELING is much more emphatic than the act or its consequences. Try and keep the situation in perspective. I think your best bet to not make this a bigger deal than it has to be is to 1) Take the higher ground if you are as "ethical" as you like others to be, and 2) Speak directly to the HR person (or their Supervisor) and explain how the employee gave out information that was not theirs to offer others since it was your personal cell/home number; explain that the customer's need was not an emergency and could easily have waited until the next day; and request firmly but politely and professionally that you do not authorize your personal information to be provided to anyone, and that you do not want this to happen again. You could also add that if someone thinks they need to contact you or would LIKE to provide a customer with your home number, it's as easy as calling you first to ask if it's OK, or telling the customer they will provide YOU with THEIR contact info. The employee can then call you on the cell/home # they already had access to and give you the info. That's a solution that doesn't leave them with NO option to "satisfy the customer." Sound good? This situation merely required a few extra steps of thinking, and the person likely was on "auto pilot" because they had the info right in front of them and someone else needed it. It's almost like anything you can see in your office tends to become "common knowledge" when many have access to it. Not sure if this is the case with you, but just an idea...

If your cell/home number is available for others in the company to reach you, the idea is they didn't find it much of a reach as a way to contact you given that it is already somewhat "public" information. Again, don't get too bent out of shape. We live in a world (and country) where there is so much harm that can be done, so many of us (overpopulation) to fit into that mix, and so many other real suffering in the world (bombs, starvation, true terror and deep personal invasion), that you should respond swiftly and professionally...yet kindly. Doesn't sound like anyone did this on purpose, and sometimes we as humans have different ideas of personal boundaries and private v. public.

Take care, and hope my advice helps you to resolve the situation at work without too much damage to anyone, and that it helps you to calm down because there are so many other things to stress about, this honestly shouldn't be one of them. Does that make sense?

You can sue him but most likely wouldnt help., or go your boss and tell them. i WOULD understand if it was a work number, but it wasn't

Not in enough trouble that the person would be terminated.

not a lot