The Information Commissioner's Office (ICO) said that drones "can be highly privacy intrusive" because they can capture images of individuals "unnecessarily".
The watchdog said organisations using drones, whether broadcasters seeking to gather footage for production purposes, police forces conducting surveillance, or construction companies to monitoring job progress, should conduct a privacy impact assessment to determine whether that use is merited.
Its new code of practice on surveillance cameras and personal information (44-page / 468KB PDF) refers to drones as 'unmanned aerial vehicles' (UAV) and the overarching systems in which UAV are used as 'unmanned aerial systems' (UAS).
"Individuals may not always be directly identifiable from the footage captured by UAS, but can still be identified through the context they are captured in or by using the devices ability to zoom in on a specific person," the ICO said in its new code. "As such, it is very important that you can provide a strong justification for their use. As with all of the other technologies discussed in this section, performing a robust privacy impact assessment will help you decide if using UAS is the most appropriate method to address the need that you have identified."
Organisations should ensure there is on/off button for recording in UAS' and have "strong justification" for continuously recording via the system. Continuous recording must be both "necessary and proportionate" for the purpose the business is pursuing, the ICO said.
Businesses using drones can help reduce the potential intrusiveness of their filming by buying systems that focus vision "in one place" rather than offering a full panoramic perspective of an area, the ICO said.
Website notices, highly visible clothing and signage telling the public about the use of drones for filming in the area can also help businesses using drones comply with their obligations to 'fair processing' under the Data Protection Act (DPA), the ICO said.
The DPA requires that individuals' personal data is processed fairly and lawfully. Organisations processing personal data must ensure that individuals to whom the data relates are provided with certain information, including who the 'data controller' is, the purposes for which the data is to be processed, and any other information about the data processing circumstances that is "necessary" to ensure the processing is fair.
"One major issue with the use of UAS is the fact that on many occasions, individuals are unlikely to realise that they are being recorded, or may not know that UAV have a camera attached," the ICO's code said. "The challenge of providing fair processing information is something that you must address if you decide to purchase UAS. You will need to come up with innovative ways of providing this information."
"For example, this could involve wearing highly visible clothing identifying yourself as the UAS operator, placing signage in the area you are operating UAS explaining its use and having a privacy notice on a website that you can direct people to, or some other form of privacy notice, so they can access further information," it said.
The ICO said that organisations can use social media too to tell the public about their intended use of surveillance technology.
"In addition to more traditional methods, it may be useful to use social media to inform individuals that certain types of surveillance systems are in operation at a specific time and in a specific area," the watchdog said. "Further links can be provided to privacy notices so that data subjects can find out more information if they are interested. This would essentially function as a layered privacy notice."
Broadcasters and other commercial drone users must only store the personal data they collect in their films for "the minimum time necessary for its purpose" before securely disposing of it, the ICO said.
Jonathan Bamford, head of strategic liason at the ICO, said: "The days of CCTV being limited to a video camera on a pole are long gone. Our new code reflects the latest advances in surveillance technologies and their implementation, while explaining the key data protection issues that those operating the equipment need to understand."