Section 43 Terrorism Act 2000: https://www.legislation.gov.uk/ukpga/2000/11/section/43 Photography Advice Met Police: https://www.met.police.uk/advice/advice-and-information/ph/photography-advice/ Threat Level (Islamic) Terrorism: https://www.mi5.gov.uk/threat-levels HOSTILE RECONNAISSANCE UK: https://www.gov.uk/government/publications/crowded-places-guidance/hostile-reconnaissance The Late Great Joan Rivers