What I did when my son was under 18 and on probation was notify the interested parties of 'red flag' activity.
It seemed to make no difference in whether he himself used or not, but I felt I was doing my part as a parent, and that was important to me.

Yes - I did do that. I guess I wasn't sure if I should have told them about the potential and specific details of his intentions, but I did - to one support person already. His counselor told me to notify my son's PO. I put a call in and I'm waiting to hear back from him. The thing is my son didn't engage in anything,yet. I also didn't want my son to know where I got my resource now - being that he could reveal more information or have actually engaged in something that he couldn't deny. Guess I shouldn't be concerned about that.

I really admire how you handled this situation. It can be almost impossible to let our loved ones experience their own consequences, and I dont think its ever comfortable. On the one hand, maybe nothing will come of your notifying probation, but on the other, whether he has legal consequences or not, you have definitely let him know you will do whatever you can to protect him and to maintain consistent, loving boundaries with him. I always have to remind myself that boundaries are there for me, too - we deserve to be safe, right? In your case, not having drug dealing going on under your roof is integral to having a safe home, and in my case, finding a babysitter for my two-year-old son and nine-month-old daughter, even when their dad is home, is integral to the safety of my home. Right now, appropriate boundaries are the part of the program with which I most struggle. For a long time, I thought of them as things I "do to other people, not things that protect me. Protecting myself, valuing my safety, is a relatively new endeavor for me, and it's one I have to develop because I'm learning I can't (and what's worse is I sometimes haven't been able to) protect my children and stepchildren if I can't assert appropriate boundaries, even if my husband gets mad about it (for example, my refusing to get into a car with him when he's been drinking).

Members who have been through different stages of addictions with their loved ones, come from a different paradgym. Sometimes, an addict can't trust himself anymore than we can trust them. For me, I'd get as much info as I could from the sending party and turn it over to the police. In my mind, this night send a more serioius message to my loved one of how dangerous it is to mess with a dealer.

i am sure you are probably aware at this point that when they stop using, if they dont get help for their personality hang ups etc...there is still a problem hence not telling the guy..i am through with all that...and instead sort going along...for whatever reason to be accepted or liked etc...
like with a alcoholic,when they stop drinking if they do not get help for the underlining personality issues of risk taking that comes with addicts...or absence of
common sense...then they are called a dry drunk...meaning...they are more likely to relapse ...
w my h the personality thing is just as hard as the alcoholism bec he is people pleaser, insecure inside but it is hidden, and also has always relied and had to have other people validation of him being somebody....although he owns his own companies etc...all tied to his addiction and risk taking tendencies...which led to gambling too.
If he was my child i would make sure that a psychiatrist counselor knew so that they can work on the underlining problems or tendencies which are his weakness that lead to the addiction and abnormal risk taking...
i dont remember how long he has been clean but it does take about a year for someone to really get it together if they work the 12 step program hard...change is difficult...but they have to really want it and sometimes it takes really hitting bottom without someone to save them or get them out of trouble for them to hit bottom which is tough love and the hardest thing to do as a parent or loved on but in the long run...they realize no more life jackets or safety nets and they have to deal with all conseqences alone...but most addicts are very self absorbed and see that as abandonment until they realize it is not a game and they can no longer manipulate you or con you or control the outcome of everything.
it is a catch 22 but all the difficult choices are...he is dipping in that seedy world by having contact with anyone still in that world...in any manner...he has to make new friends that are clean or never used drugs because those old friends are HUGE RED BURNING arrows.............i think he is also probably aware he should not be in contact with any users or dealers ...that is against his program.
I also had to remind myself from time to time that drugs or alcohol actually damages the brain and can take up to a year for it to build back on top of the new life they are leading so...they is why the rules are so strict that they have to follow...as a guideline until they really are 2 years on the other side of the fence and then it is a routine and habit and not rules.

Update: Besides figuring out what the drugs were that the boys were talking about on-line, I also found a homemade bong in his room today. So far his support team knows about the drug talk (including his PO) but they don't know about the latest. His PO said to keep an eye out and see if this kid's name pops up again on-line. He said he doesn't have enough to violate my son, which means going back to court. I wasn't necessarily looking for that as much as having an intervention to see if he will admit for that he would go back to treatment. We've done that before and it worked. I would use the bong as a leverage - telling him that I will report the possession of drug paraphernalia, if he doesn't cooperate. Not sure if this is the way to go, or not.

What would you do?

Wow, what a lot you have going on! It sounds like you want to get your son into treatment, and it also sounds like telling your son's PO about the bong would accomplish that. Is there a reason you can't have another intervention? I've heard they can be expensive, but I don't know first-hand. I know it's probably important to you to feel like you're making a difference and that he knows how much you're working on his behalf. I haven't had to deal with this issue in a child, but with my husband, trying to leverage him has never been anything but damaging to our relationship. I try to keep my boundaries, which means I report illegal activity, which in my case means I call the police if my husband drives off drunk in the car. Although that has not resulted in any legal consequences for my husband, I've done what I can, and if God forbid the first time the police catch hold of him is when they're scraping him off the sidewalk or taking someone else to the hospital or morgue, there will be a paper trail, and I'll not have to deal with the additional guilt of enabling him to "get away with it." Only you know what decision is right for you in your situation - the best guidance I can suggest is that you consider what actions will bring you the greatest peace, regardless of an outcome you really can't control. It's not the most fabulous place to be, but the reality is that you can do everything for your son EXCEPT his recovery, and sometimes, the more we do for our addicted loved ones, the more we actually HINDER their recovery. Good luck to you!

Almost 28 years Alanon here and this is what I did with my daughter before she turned 18. I put her in treatment. I did everything I could to stop her while I still could. She did something to get arrested, she went to jail. And I did everything I could to NOT stand in the way of consequences. I would turn in the evidence to his PO. Even with my ex, every time he relapsed, he went to jail. I told his PO, I did NOT stand in the way of consequences. Talking to old "using" friends, talking about selling drugs and the bong are all RED flags. "People, places and things"!!!! If he hasn't relapsed yet, he's heading there. NO doubt in my mind. Good news...because I didn't stand in the way of the consequences, my daughter has not had a drink or a drug in 4 years now. And she is doing great...a wonderful mother and a responsible, young adult. At 25 she has completely turned her life in a new direction.

Let the kid be.

I can't stop parenting but I think I do need to step back.