I encrypt everything except totally harmless messages (I only skip encrypting those to not aggravate the recipient, honestly). But I don't think it's such a bad thing if someone doesn't. With a hidden Tor service, everything is end-to-end encrypted. The only reason to encrypt your address is if you're worried SR isn't really purging it and if the site is ever seized, a record of the order and address will exist somewhere.Also, depending on how you print out the address, encrypting it may just be incentive for vendors to leave the file sitting around on their hard drive. Most programs work on files, so it's probably going to be saved somewhere at least momentarily (though naturally you'd know better than me -- I'm just a buyer).Anyway, just my .02 BTC: it's not as insecure as you might think.