Nevermind, I think I'm just thinking of some misinformation I came across some years ago regarding california poppies (these are legal and extract has been smoked for recreational effects but alkaloids are different than those you're probably thinking of). Here are some quotes from thread on this subject on a gardening forum, I hope they help:
After getting douched in the thread linked above I quit posting links. I found another site that reported that the most serious problem one has with poppies is that they may give law enforcement broader search and seizure rights than they might otherwise have. So, if you have illegal DVDs or guns (legal or otherwise) or whatever and your neighbor calls the local cops and says TreeDazzled is growing poppies in a pot
on his deck then they come and go through you house and seize you DVD player. Statistics show the most serious risk in growing poppies is getting you guns confenscated, should you have any, even if they are legal.
Chances are that your extension agent won't know either. All poppies have alkaloids of varying forms and strengths. Illegal varieties are all those that are specifically P. somniferum according to the law. Don't worry about it. The poppy
police are few and far between and most don't have a clue what they look like anyway. Besides, intent to distribute an illegal drug
is far different than having a few 'breadseed' poppies in the yard with other garden flowers.
The bottom line is that it is legal to own/buy the seeds. It's the plant that's illegal. Like rosa said, the poppy police
are few and far between. Because most of the neighborhood children where I live are turning into teenagers now, I only grow my poppies and other plants that might be interesting to them in my backyard.
Unless it appears that you're growing opie poppies for pharmaceutical purposes, the police could care less about what you grow for flowers.
I did a study of this and I thought I had reported somewhere here that the legal people say the legality of poppies per se is not particularly interesting. The legal people say that the use of the drug laws to dilute your search and seizure protections makes growing poppies a problem if you irritate your neighbors or the sheriffs depute. The case that is working its way up through the courts has to do with someone in Washington who had a few poppies and a gun collection but he had a quarrel with his neighbor. So the neighbor called the sheriff and the sheriff confiscated his antique guns.