I believe we resolved this in a ticket for you, in case others need this info, the new API for Facebook requires curl in php, if you are seeing this issue, enable/install curl and you should be all set. If not please file a support ticket and we can help you.
There is no way to see this I'm afraid, this could have also been a targeted attack, humans also register and then pass the login details off to bot engines to post etc. I would tighten up your question and answer maybe, make sure it's not a color or math question, and base it on the topic of your community.
There is flood control if you have it set, but it sounds like the issue in your case is you don't have the ips Spam service setup properly to block accounts with high ratings (block on level 3 & 4) , nor the question and answer validation setup on registration? If you have those items in place, spam is nor normally an issue. To clean this up, set your spam service settings to ban, and delete all content when flagged as a spammer, then mark the users as a spammer, it will delete the items, and ban the user etc.
We do, we have, and we will always improve on SEO as things change. What most don't understand is google and other search engines are an always changing item, their goal is to find what you are looking for , as site owners often hack their way around into fooling/tricking/seo'ing google and others to list their site higher without actual valid "high rated" content, google and others are always looking for methods to rank content properly, and see their way past the tricks people play, they will in time find a way to de-value the bad content and rank appropriately. If you want to rank high for something, you better have high value content on your site, that is the bottom line, if you do, you will never worry about SEO again.
Rhett you are the best you have helped me out so much Thanks for trying to help with my issue's i have had if there was a feedback system for each staff member if there was a 1 out of 10 i would pick 10 because you are the best thank you