Youtube uses a flag system that allows users to report videos as inappropriate which according to Youtube means any violation of the Youtube terms of service. A flagged video will be reviewed by an administrator who has numerous options at hand including setting the flag for age verification which requires users to login before they can view the video. Age verification is pretty basic and anyone who cheated on his birthday can watch the video after logging in.
Also Read: Watch Youtube Age Restricted Videos Without Logging in (Simple Trick)
The message that gets displayed when a user who is not logged in loads a video with age verification is the following: “This video or group may contain content that is inappropriate for some users, as flagged by YouTube’s user community. To view this video or group, please verify you are 18 or older by signing in or signing up.”
Numerous ways to bypass that age verification check have been posted which included using caches and proxies. The Firefox extension You Old Enough provides users with another way. The experimental add-on will check if the video on Youtube is flagged for age verification and open it immediately in a popup window.
Also Read: Hacking Youtube to find good quality videosThis means that it is possible to watch all videos on Youtube that require age verification without having to login to the system.