Bear in mind they were not in a public place, but a conference venue - which would almost certainly be private property. It is totally legal to prohibit photography in such cases.
However, normally this has to be made explicit (through signs, or the like) - it's assumed it is allowed unless otherwise stated.
I wonder if going forward conferences will consider banning photography in future, for better or for worse.
However, normally this has to be made explicit (through signs, or the like) - it's assumed it is allowed unless otherwise stated.
I wonder if going forward conferences will consider banning photography in future, for better or for worse.