I’ve had problems uploading videos on my iMac and spent much of last night and this morning speaking to Apple support who have concluded that due to the political content of my videos, and having exhausted their usual list of technical solutions, YouTube has blocked my account, most likely following a complaint for some reason. 
Does anyone have any idea who to contact at YouTube to resolve this? I have spotted a phone number in San Fransisco, but it is 5am over there, and when I called on the off-chance, I was referred to a website. All I can do is fax over my query and ask them to resolve this, unless you can come up with a better idea.
Thankfully, I can still upload videos by saving them on my desktop first and using a different upload technique, so I am not totally snookered.
The last video I published before these difficulties began was about Cambridge’s parliamentary candidate Nick Hillman winning over the student vote which I published last weekend. 
It would appear that someone, somewhere doesn’t like what I have been recording….. 😉
Hi Ellee, I think it may be a little less drastic. YouTube have made changes recently that seem to impact disproportionately on Mac users – I’ve had a video churn all night to upload and then fail in processing. The default iMovie/FCP codecs seem to really upset the YouTube systems these days. Try saving in a different format and re-loading – I know it’s a pain but it seems to work for me.
HIghwaylass, I have two other YouTube accounts which I manage for clients and they work fine. I’ve tried them both, it is just my account. And I’m only repeating what Apple said, it was their idea about being blocked, not mine.
It isn’t blocked all your video’s are still available for public viewing – must be like Highwaylass is saying above
Hi again, I’ve sent a fax to YouTube and hope they can help sort this out. Apple support thought it was strange that one account holder running three accounts could publish a project under two accounts, but the same project would not upload the normal way for the third account which is in my name. It is something they haven’t experienced before, and several times she went off and spoke to supervisers and asked their advice. We tried all the obvious, the cookies and spam, and we talked through the different formatting too, which is what I am doing now. I’m certainly not looking for any dramas here, just clarification. It was their idea that YouTube has put a block on my account on the recommendation of a third party; it was all they could suggest after exhaustive attempts to publish to YouTube in the usual way.
With the content that is posted daily on YOUTube, I find it unlikely you have been blocked because of content. I had a problem with my facebook acccount for a while and it was just a snafu. You simply need to persevere I think. Keep at it.
If YouTube block any of your content they always inform you by email.
I have had problems uploading from time to time and I just have to change the format that I use to upload.