Complex sentence: Because a free pop music concert and fireworks show was planned, sections of Millennium Point were fenced off and either marshals and/or police stationed at a few points so as to prevent any minor crimes, like pickpocketing.
Split into simpler sentences: Because a free pop music concert and fireworks show was planned, sections of Millennium Point were fenced off. Either marshals and/or police were stationed at a few points so as to prevent any minor crimes, like pickpocketing.