Comment 4 for bug 341935

3) In combination with #1 and/or #2, limit the number of "Complete your registration" messages sent to any e-mail address to ~2 per day and ~4 per month. (For bonus points, count <email address hidden> and <email address hidden> as a single e-mail address.)

4) Use a text-only (e.g. math) captcha. This would be no problem for Launchpad's target user base, i.e. software developers, but would make it (even more) important for shop.canonical.com to stop requiring every customer to have a Launchpad account.