Cellphone rights guide - not just for protestors

You are allowed to photograph or take video so long as you are in a public space. On private property, rules may be slightly different, but in general law enforcement can't view or delete media on your smartphone without your permission.
MORE:
http://www.slate.com/blogs/future_tense/2014/11/25/cellphone_rights_guide_for_protesters_in_the_united_states.html