This aint new, happens time to time in Youtube. They do a mass clean up or shit... and kills all accs that even remotely looks suspicious.
To the peepz suggesting "aged" accs... i spam like a mofo, over 50k-100k/day... hav used both aged/new accs... main thing is, if u r gonna spam ruthlessly, even a 10 year old acc won't last. My fresh accs last as much as those "aged' accs... only difference is you pay a great deal of price for practically no difference.
Spamming will kill your accs sooner or later regardless of age. The trick is to handle the accs in such a way, so that you can atleast make em last for a while. Proxies, captchas, comment flagging, posting spammed comments and comment count per acc all of them are factors. It also depends on how much you comment per acc. If you r gonna spam 200-300/acc per day, then you're asking for it. If you encounter too many captchas in an acc, even thats bad.
None of my accs faces any captchas... it took a while, but I figured out how to completely bypass the captchas, without lowering the quantity of comments i post daily.
On the other hand, if you're gonna upload vids, then by all means use an aged acc.