One reason for doing protests is as community-building. This can happen both at the protest itself, but also if you invite the media, you get to inform the public that the movement exists, and they can join it. So you can justify your presence as contributing to exponential growth: a ‘force multiplier’ as they say.
See you in the morning at Downing Street!
We got 4 minutes on Channel 4 - hopefully more coverage elsewhere to follow.