YouTube has implemented a new feature called "Checks" using its "Content ID" system, which is designed to make it easier for filmmakers to see if audio or video components of their clip are in violation of copyright or advertising guidelines as they are uploaded, thus preventing its monetization.
This is a big step up from YouTube&s previous practice, where potential copyright infringement or policy violations by videos were not detected until sometime later after the upload, making it difficult for the creator to respond promptly to a demonetization or deactivation of their video. One way was to leave the newly uploaded video unlisted or private for a while and not publish it yet to see if the copyright (on the sound or images) was claimed by someone else.
Often the video owner also lost revenue for the duration of the dispute - even if it was later decided in his favor.
If, on the other hand, a copyright or content warning is issued when a video is uploaded, the filmmaker can react immediately and correct the relevant part of his or her video that is being disputed or dispute the copyright claim even before the video is published. This means that there is no need to go through the classic objection process after publication, while possibly missing out on advertising revenue claimed by the alleged copyright holder.
YouTubers can then, in the case of an objection, either wait until the dispute is decided by YouTube before publishing the video, or they can publish the video while waiting for the decision. If it is decided that the creator did not use copyrighted content, the advertising revenue generated during that time will be paid out without having to suffer any losses for the duration of the dispute. On the other hand, if it turns out that the copyright claiming counterparty is right, the advertising revenue will be paid to them instead.
Copyright checks are usually completed within 3 minutes, while monetization checks can take a few minutes longer - a time estimate is displayed on the screen during the check. Copyright claims may still occur after the fact, but these cases should now be far less frequent than before after a successful pre-check.