Surveillance of protests has skyrocketed in recent years. The impact of intrusive and disproportionate surveillance on the right to privacy of protesters has rightfully been the subject of scrutiny by courts, civil society and the media.
What has been under-explored, however, are the impacts on other human rights, particularly the right to a fair trial. At Privacy International, we investigated and analysed uses of data obtained through the surveillance of protesters as evidence in criminal proceedings in jurisdictions across the world, including the UK.
Intrusive surveillance: a legally risky global trend
Across the globe, law enforcement agencies are deploying surveillance technologies - often in secret and without clear legal frameworks - to monitor protests. From facial recognition technology (FRT) to body cameras, these tools are being used to collect vast amounts of data about protesters. While these technologies are presented as measures to maintain public order, they often come at the expense of individual rights, particularly the right to privacy. The resulting data is also frequently used in court against those participating in peaceful protests.
This use of surveillance evidence is problematic for several reasons. Such data is often collected in secret and without a legal basis that respects human rights, including privacy. The lack of transparency about how and when surveillance technologies are used and who has access to the data generated makes it difficult for defendants to challenge the evidence presented against them and can lead to abuses such as the deletion of exculpatory evidence.
The failure to adhere to safeguards, such as only using surveillance technology where there is a reasonable suspicion that an individual has committed a criminal offence, when coupled with lack of understanding of the probity of such evidence, means that it may be presented in misleading ways.
This risk is heightened by the growing development of AI and black-box machine learning tools for use in law enforcement investigations. The opacity of such tools challenges the right to adversarial proceedings and increases the probability of miscarriages of justice as individuals are less equipped to contest adverse inferences drawn by algorithms, including where they are based on misleading or inaccurate surveillance data.
These failures ultimately undermine defendants’ ability to mount an effective defense. Two examples from the UK and France underscore these concerns.
UK case study: bodycam footage and the right to a fair trial
In the UK, the case of two protesters involved in the Black Lives Matter demonstrations in 2020 reveals the dangers of unregulated surveillance. The two protesters were accused of assaulting police officers during a protest. However, it was later revealed that bodycam footage from police officers - which could have exonerated the protesters - was not disclosed to their defense team. The footage showed the protesters being pushed and struck by officers, not the other way around.
This case highlights a serious issue in the use of bodycams and similar surveillance technologies. While bodycam footage is intended to provide transparency and accountability, the failure to disclose exculpatory evidence is not compatible with the right to a fair hearing. It also places an unfair burden on defendants to prove their innocence, rather than the prosecution having to prove guilt.
France case study: surveillance and house arrest during protests
In France, the 2015 terrorist attacks led to widespread use of surveillance and restrictive measures during high-profile events like the UN Climate Change Conference (COP21). In 2015, the authorities placed two brothers, known for their environmental activism, under house arrest as they were suspected of planning a protest that the authorities considered could become violent. These restrictions were based on intelligence reports, referred to as “notes blanches” (‘white note memos’), which are so secretive that there is no publicly available information about the provenance of information included in them. Information provided to us by a French NGO suggests that the reports included mobile phone metadata and social media monitoring.
The brothers challenged their house arrest orders in court, eventually taking their case to the European Court of Human Rights (ECtHR). The court ruled that one brother’s house arrest was justified due to sufficient intelligence, but the other brother’s arrest was deemed unlawful because the intelligence was not adequately substantiated.
The case highlights the danger of relying on opaque, unchallenged intelligence, which was apparently not sufficiently interrogated in the French courts, undermining key principles of due process, including the presumption of innocence and the right to a fair hearing.
Why these cases matter
Both cases illustrate how the growing use of surveillance technology at protests threatens the rights of activists and protesters. The failure to disclose crucial evidence and the lack of transparency in the use of surveillance technology resulted in significant legal and human rights concerns.
When secretive surveillance data is used as evidence in criminal proceedings, it becomes difficult or impossible to challenge and places individuals in a position where they must prove their innocence.
To prevent the abuse of surveillance technology and the unfair use of data in court, there is an urgent need for clear safeguards. These safeguards should ensure that surveillance technologies are used in a manner that respects privacy and human rights, with strong oversight mechanisms in place to prevent abuse. Furthermore, it is essential that data collected through such technologies is not used in criminal proceedings unless it has been obtained lawfully and can be fully scrutinised in court, including through full and effective disclosure.
Conclusion: the need for reform
As the use of surveillance technologies in protest settings grows, so too must the legal frameworks that govern them. Governments must ensure any data collection complies with human rights law, with transparent procedures in place to safeguard the rights of individuals. Moreover, courts must be alive to downstream fair trial concerns where the right to privacy is breached and develop novel holistic safeguards. Without these reforms, the use of surveillance during protests will continue to undermine the right to dissent and erode fundamental freedoms.
Legal practitioners must remain vigilant and demand greater protections for individuals caught in the crossfire of increasingly intrusive surveillance. Only through robust legal reform and continued advocacy can we ensure that our fundamental rights remain protected in the face of this technological onslaught.
About the authors
Caroline Wilson Palow is Privacy International’s Legal Director and General Counsel. In those roles, she leads PI’s legal advocacy and counsels PI’s programmes on legal strategy and risk. Caroline also leads Privacy International’s programme of work on Defending Democracy and Dissent, which investigates the role technology plays in facilitating or hindering participation in civic society.
Jonah Mendelsohn is a lawyer and Legal Officer at Privacy International. He works on legal advocacy and litigation challenging surveillance and other invasive uses of technology by both governments and corporations.