“Senior managers at Crossrail, the huge publicly funded rail project in London, hired a corporate security company to monitor trade unionists who were campaigning against blacklisting across the construction industry, previously secret documents reveal. The managers paid £59,000 to the company, Control Risks, over three years. They said the monitoring of the trade unionists was part of work to protect the project from outside threats.”

https://www.theguardian.com/uk-news/2019/jul/29/revealed-crossrail-hired-security-firm-to-monitor-trade-unionists