High-profile YouTubers have been targeted by cybercriminals over the weekend in what appears to have been a highly coordinated and "massive" attack. FORBES The security warning was made by Catalin Cimpanu, a ZDNet reporter, who spoke to a member of an internet forum with a history of trading access to hacked accounts. Here's what we know so far and what you need to do to protect your own YouTube account. Which YouTube accounts have been hacked? According to the ZDNet investigation, many ac...