Under the Serious Organised Crime and Police Act 2005 and the Terrorism Act 2006, there are areas designated as 'protected sites' where people are not allowed to go. Previously, these were military bases and nuclear power stations, but the law is changing to include other, generally political areas, such as Downing Street, the Palace of Westminster, and the headquarters of MI5 and MI6. Previously, trespassers to these areas could not be arrested if they had not committed another crime and agreed to be escorted out, but this will change following amendments to the law.