George Clooney revealed details last week about “his” spy satellite over Sudan, which he funds to keep an eye on the Sudanese president Omar al-Bashir, who has been accused of war crimes.

The Satellite Sentinel Project (SSP), which Clooney co-founded, has been innovatively using information from satellites to help prevent humanitarian disasters before they happen – rather than reporting the aftermath of a conflict. Near real-time satellite data, provided free by one of the worlds biggest commercial satellite operators, DigitalGlobe, is used to deter atrocities and to monitor military movements along the troubled border of Sudan and South Sudan, enabling responses that avoid civilian casualties. As the SSP motto goes: “The world is watching because you are watching”.

Other advocacy groups like Amnesty International and Human Rights Watch also use satellite images to monitor human rights abuses. Images taken of Burma, Syria and Zimbabwe have shown the destruction of civilian areas, including razed villages and bomb damage. These can be quite powerful for those seeking to raise public awareness and pressure for political intervention, aid or sanctions. Their increasing value in this area is supported by the fact that the Office of the Prosecutor of the International Criminal Court now has its own in-house team with an expertise in satellite data.

Step changes in satellite technologies, particularly the increased availability of data at scales which allow the identification of ground-based objects, are obviously providing exciting new opportunities for NGOs to monitor remotely. But they also raise questions about who else is using satellite images for monitoring purposes, and what they are using them for.

In practice, governments have for used satellites for many years, especially to police extensive areas where ground inspections would be a burdensome logistical exercise with high associated costs. Within Europe they are used by regulatory bodies to monitor fraud for farming subsidy payments, to patrol borders for oil spills and boats carrying illegal immigrants, and to check compliance with legislation concerning the environment, deforestation, and water usage. There are also examples of the police using archives of satellite images to investigate crimes.

Satellite data also have a growing commercial value. Insurance investigators in the US proved that a couple in New Orleans committed insurance fraud after satellite images taken before and after Hurricane Katrina revealed that the damage to their house actually occurred after the Hurricane. Images were purchased after investigators considered that the damage to the house did not look like other Hurricane damage and appeared to be man-made.

But as is so often the case, we are also starting to see a pattern of move, counter-move and counter-counter-move when satellite images are used to track people.

Urban legend has it that EU subsidies to Italian olive growers nosedived after a satellite monitoring programme was introduced, then inexplicably started growing again. It is said that farmers had been planting cheap umbrellas which looked like olive trees on the satellite images to make it look like they were growing more than they were.

Clooney has also revealed that awareness of his satellite programme has led to a change of tactics. Attacks now only happen “at night or under cloud cover,” when the satellite cannot see what is happening, he says. The counter-counter response from Clooney’s team was to switch to infrared satellite monitoring that would pick up activity in the dark.

What’s more, even when a Hollywood star is involved, the reality of using satellite monitoring is quite far from the portrayals found in Hollywood movies such as Enemy of the State. Commercial images can be expensive and there are limits to what this technology can detect. Few evidence-gathering technologies work optimally in isolation and satellites are no exception. However advanced the technology, the actual interpretation of the photographs can also be wrong or used by those with certain agendas. A significant element of the US case against the Iraqi regime in the UN Security Council in 2003 centred on satellite photos claiming to show the existence of chemical weapons sites and associated equipment used for transporting weapons of mass destruction. Checks on the ground still provide the best answers.

Who’s in charge here?

Earth observation using satellites is now at a crossroads. Better resolution means that more information can be gleaned from images but also that privacy could become an increasingly important issue. Research undertaken by UCL show that concerns already exist regarding satellite monitoring and privacy. In a survey, 58% of Australian farmers and 75% of UK farmers agreed that satellite monitoring could be an invasion of privacy.

Many satellites, such as the ones used by Clooney, are not owned by the state but are built and operated by private companies. These are not subject to many controls, primarily because of an international “open skies” policy that has operated since the 1950s. No government has control over regulating what satellite images can be sold or restricted in any area. While they have some regulatory powers in respect to the flying of civil drones, fully commercial companies can control a potentially invasive technology relatively unregulated.

The European Commission plans to investigate the issue of privacy as it relates to the use of civil drones but there has never been a review or even public debate about what we consider to be acceptable and intrusive monitoring from satellite technologies. Whether they are used for good or not, it may well be time to regulate the technology or at least clearly define the boundaries of privacy rights in this area.

Laws are by their nature reactive and slow to evolve, but as satellite technologies could have profound social legal impacts, both positive (as in the case with Clooney’s monitoring programme) and negative, policymakers surely have to be bold and plan in advance of future technological step-changes.