They're going to keep coming back too. I've been saying this since the outset - it is a bot that is doing it. Look at the comments posted by these "users" one word, which makes little sense in most contexts. As I suggested previously, either a delay between registration and posting being attachments being allowed or a restriction on registering with Launchpad using an ID in the format used by the bot might be worth considering.
They're going to keep coming back too. I've been saying this since the outset - it is a bot that is doing it. Look at the comments posted by these "users" one word, which makes little sense in most contexts. As I suggested previously, either a delay between registration and posting being attachments being allowed or a restriction on registering with Launchpad using an ID in the format used by the bot might be worth considering.