If you've ever tried moving from Google services to another platform, or if you like to have a local copy of your data, you may be familiar with Google's Takeout feature. Essentially, it lets you download your personal data from multiple Google services so you can save it elsewhere. This, of course, includes Google Photos, but if you used Takeout to download videos from your account last November, they may have ended up being sent to someone else.
Twitter user Jon Oberheid shared a snippet of an email from Google which was sent out last night, alerting users to the possibility of their videos being sent to someone else. Specifically, the email says that if you requested a backup of your Google Photos data between November 21 and 25, your videos may have been sent to someone else, if they happened to be downloading videos from Google Photos at the same time. This might have resulted in your archive being incomplete or containing videos from someone else.
If you happened to be affected by this issue, Google's recommendation is that you export your data again and delete the previous backup. Of course, if your videos were sent to someone else, that won't alleviate your concerns; you just have to trust that whoever received your files will delete them. On the bright side, photos were not affected.
According to Google (via 9to5Google), only 0.01% of users who exported their date using Takeout were affected, and no other Google services were involved. Actual pictures on Gooogle Photos were also not affected, only videos were.