Google says it fixed the issue two hours after it was discovered.

Fans of singer Justin Bieber were targets of a cross-site scripting vulnerability in YouTube, reports eWEEK. The vulnerability allows attackers to insert HTML code into YouTube pages devoted to Bieber. Fan were redirected to pages containing adult content, as well as being bombarded with numerous pop-up messages.

Google says it fixed the issue two hours after it was discovered, according to TheCelebrityCafe.com. A spokesman says:

We're continuing to study the vulnerability to help prevent similar issues in the future.