Also IMSI catching is used widely by police. https://news.vice.com/article/vice-news-investigation-finds-signs-of-secret-phone-surveillance-across-london https

Also IMSI catching is used widely by police. https://news.vice.com/article/vice-news-investigation-finds-signs-of-secret-phone-surveillance-across-london https://news.vice.com/article/vice-news-investigation-finds-... And none of this surveillance compares to the extent of surveillance in Nothern Ireland.