Open source information gathering
‘Open Source’ refers to information from any source that is available to any citizen. In terms of surveillance work, this would include walking past a suspect’s house to verify its existence. Open source also includes publicly accessible documents (such as the voters roll in the UK or executive appointment tax and asset declaration forms in the US) held in paper or electronic format. In most cases, Open Source relates to internet searching, which includes free and fee-based sources and databases. A number of well-known techniques can help focus and target searching, often known as Deep Web Searches.