This can be accomplished by placing spamtrap addresses on your web site. These addresses must never be used for anything other than clearly designated spamtraps.
The basic idea is that when you designate a spamtrap, you are agreeing that any spam that arrives there is worth investigating and potentially pressing charges against the spammer. At the minimum, you are saying that you will follow up and insist that the spammer demonstrate, in a legally acceptable way, how they obtained the address.
It is this threat of real, enforceable, legal action that makes the spamtrap into a 'landmine'. It will force spammers to be more careful about where they get their lists of email addresses. Failure to do so could result in real legal consequences.