Someone recently mentioned using Eventbrite or similar for organising the next Excel Conf (I have not heard more, so no idea if anything is in the offing or not).
Their latest agreement that you sign up to (after reading carefully I’m sure) grants them (amongst other stuff) the right to enter your event , and pre and post setup/teardowns, take as much video and photos as they like of anything they like, for them to use whenever, where ever they like for ever!!!
That also means you grant them right to publish photos of any and all attendees any time any where.
Dunno if it applies in the UK/EU
What an outrageous rights grab