I was wandering an Artist Alley, and I found out a couple weeks later that somebody had been filming for their vlog and that I was visible in the background. It was incidental; I wasn't doing anything besides shopping, and I wasn't being singled out, but I was noticeable enough that several people were able to identify me and let me know about it. I have a lot of experience with appearing on camera from many of my past livestreams and interviews, but realizing I'd been filmed and uploaded to the internet without my knowledge or consent made me extremely uncomfortable.
Since then, I've learned how to blur faces in Adobe Premiere. While I very rarely encounter the issue in my own videos, I intend to make a conscious effort going forward to take this simple step when uploading anything that random strangers may appear in.
If you are a vlogger that films at cons, please make sure you are being considerate of other attendees, staffers, and vendors. It's already extremely bad form to film in the Artist Alley (as artists are often worried about their work being stolen/fed into AI/etc), and I know of con-goers that have dealt in the past with issues like harassment and bullying who could potentially be hurt in ways you may not anticipate by being filmed at a particular convention. As content creators, we have a responsibility to be mindful of the privacy of others, even at a public event.
Rock on, guys, and never stop drawing.