Can someone take photos of me in a public space?

Generally speaking, people can take photos of you in public without your consent, unless:

• you are in a place where privacy can be expected (such as changing rooms or bathrooms);
• any film or photos would be highly offensive to an objective and reasonable person;
• they have no legitimate reason for the film or photos;
• it could stop other people from using and enjoying that place. 

 
If someone has filmed or photographed you in such a place, it may be appropriate to report this behaviour to the Police by calling 111.

Another thing to note is that many rainbow centred events would most likely be understanding if you were uncomfortable being photographed due to privacy and would allow you to sit in an area where no recordings or photographs are taken. It would pay to approach the event organisers directly around this.