Hi Gijs,
Thanks for cleaning up the spam. There has been quite an attack recently. We're tracking fighting it in this ticket:
https://github.com/ros-infrastructure/answers.ros.org/issues/76 It appears that we may be fighting an actual person or a bot capable of getting through a CAPTCHA which has recently been added for posting below 10 Karma. I believe that in the long term cleaning up the spam quickly and completely is our best approach as it will remove the reward for spammers.
Our standard policy is to delete any spam post immediately and block the user account. After being blocked the user can only contact the moderators using the feedback link.
If you encounter spam just click the "Flag Inappropriate" button and it will be queued for moderators to review. Or if you have enough karma you can just delete it immediately. However if you do delete it, please flag it first so the moderators get notified and can block the account too.
Luckily it's a busy site and many hands can make light work.
Tully