On of the many reason why you should always delete the source identifier.
youtu.be/dQw4w9WgXcQ
^This is the link to a video
youtu.be/dQw4w9WgXcQ?...
^This is the link to the video but with added information about me
Whenever you share a link delete "?si=" and everything after.
oNoise
Security alert: YouTube added a feature that now puts your username in shared links, so if you share a YouTube link on here, everyone who clicks it will know your YouTube username.
To turn it off, go to Settings - Privacy and turn off "Channel visibility for shared links"