This What's happening website uses the following third party cookies from Smartsurvey:
ASP.NET_SessionId – Session cookie and is used to keep track of a respondents progress in a form
SX_X – This keeps track of completed forms to prevent multiple responses
This website also uses browser local storage to save the clicked state of "Are you going" buttons on What's happening event pages.
This is a work in progress. Help us improve it.