As above, attempting to purchase or receive a controlled substance is illegal. However, when the Farmer's Market was busted, some buyers' names and addresses were recovered and they were sent "stern warnings" from the DOJ (some people in this community got the letters) but as far as I know nobody has been prosecuted outside of the core people behind FM. An address alone isn't evidence of attempting to purchase something, since you could have sent your address to a vendor and never gone through with the purchase. However, the transaction history on SR might be valid evidence of drug purchases. At least items are deleted after 6 weeks, though I think that should be shorter.