Re: London / UK Riots
Yes you can - as per the The Terrorism Act 2000 passed by British parliament - The first section of the act defines Terrorism as:
Section 1. -
(1) In this Act “terrorism” means the use or threat of action where-
(a) the action falls within subsection (2),
(b) the use or threat is designed to influence the government [or an international governmental organisation][2] or to intimidate the public or a section of the public, and
(c) the use or threat is made for the purpose of advancing a political, religious , racial][3] or ideological cause.
(2) Action falls within this subsection if it-
(a) involves serious violence against a person,
(b) involves serious damage to property,
(c) endangers a person’s life, other than that of the person committing the action,
(d) creates a serious risk to the health or safety of the public or a section of the public, or
(e) is designed seriously to interfere with or seriously to disrupt an electronic system.
(3) The use or threat of action falling within subsection (2) which involves the use of firearms or explosives is terrorism whether or not subsection (1) (b) is satisfied.