With sometimes hundreds of people joining in a day, that's not as easy. Besides, most of the spam we get is from people who seem "innocent" when they join and only then do they their dirty deeds. The ones we had join today are obviously not typical.
John you are way off on this one. While I don't have nearly the problem with my network that I had before, some months ago I was spending a good 15 minutes every other day open every single pending membership, checking if it was spam, suspending or approving it.
If you add a new required profile question as suggested in #4 under "What You Can Do To Stop Spam" on the Spam Updates page, you should see these stop, at least temporarily, and possibly for quite a while.
That doesn't actually solve the problem, any answer given will still let them sign up. We need to have a system where you can designate a "correct" answer on such a multiple choice question and the wrong answer will lead to the profile being automatically rejected for your suggestion to work. And isn't that just another version of the captcha-idea?
Actually that will solve the problem for large scale automated attacks. I had over 100 pharmacy spam signups a day on my network a couple of months ago, and have had none since implementing that question. The reason it works is because it's not a person filling out the form, it's a script/bot. When you add the new required question, you are changing the values that need to be sent by the script in order to successfully create a profile. Until a human looks at your network again and updates the script, those profiles won't get created. When that happens you can delete the existing question, and add a new one, which again changes the values that need to be received in order for a profile to be created successfully. You are correct that this won't stop casual human spammers though.
Work is going on now to let you create a question with a correct answer as you've suggested above, and that will help deter multiple types of spammers. You should definitely consider implementing a verification question on your network as an interim measure though; I suspect it will help.
The only way to stop spammer from affecting your network is to moderate membership and moderate your blog.....If you dont do this, when you are sleeping the spammer will make their move and hope many of your members buy China fake Viagra pills before you notice and delete their post.
The only other way is for NIng to give us the ability to block IP address, the same person sign up everyday on our network and we block them everyday....