You probably got hit with a number of DMCA takedown requests. You've filed a counter-notice, which will put the content back up. But you have to wait until that occurs, which could be a while. You may not have done anything wrong, for this to occur. All it takes is someone willing to _say_ that you infringed on their copyright. I think you can sue the issuers of the takedowns, if they are fraudulent.
You can, but good luck. Filing a counternotice gets you the name (and I think the IP address) of the person that filed the notice, but considering that #1 is just a form input box and #2 is useless for identificiation purposes... This was likely the act of someone with an axe to grind, not any violation of YouTube policies.
http://www.youtube.com/t/copyright_counter
The final line reads:
> We may then reinstate the material in question at our discretion.
So it's a toss-up if they're actually going to do something but they will reveal your information to the party that claimed infringement. That seems to be a pretty lousy deal.