There are many who do not want to see advertisements and they try to avoid paywalls on the Internet, by installing ad blockers or other complex solutions. As it turns out, in many cases, overcoming these “barriers” is often as simple as adding a period to a URL.
In other words: Suppose you are not a YouTube Premium subscriber, “youtube.com/gamatovideo” will display ads, but “youtube.com./gamatovideo” will not. It is so simple.
The bug is mostly limited to desktop browsers computers, but to cell phones, you can use the “desktop site” option to make the trick work.
Redditor u / unicorn4sale reported the error to subdreddit r / webdev. According to unicorn4sale:
"It's a commonly forgotten case, websites forget to normalize the hostname, and the content is still displayed when the hostname is not matched in the browser. So there are no cookies and CORS. Many sites use different domains to display ads with a list of permissions that does not contain the extra dot. "
In other words, it's simple blindness and it doesn't just work for YouTube. A quick test showed that it is effective and bypasses paywalls on the pages of The New York Times, Wired, The Washington Post, The Atlantic and many more
Of course, now that the bug has been made public it is only a matter of time before it closes. Enjoy it as long as it lasts.