We have powers to use a variety of technical surveillance methods. For example, we might covertly monitor a subject of interest using visual surveillance, tracking or interception devices.
With the proper authority, and when necessary and proportionate, we may also carry out a search of premises or devices. We generally carry out such activities in a way that the subject of national security interest is unaware of our interest in them. There are occasions, however, when we will execute our search powers openly.
The use of technical surveillance and search powers almost always requires a warrant.
We do not have any enforcement powers and cannot detain or arrest someone, or require them to speak to us.