Cloud storage firms are facing an investigation over the prices they charge to internet users by the Competition and Markets Authority (CMA).
The CMA said that some users may be being charged unfairly, and some providers of cloud storage may be breaching consumers laws.
It will investigate concerns over prices going up after a contract has been taken out, the amount of data being changed, user data being lost or deleted, how contracts are automatically renewed and what happens to data if a user cancels their contract.
Earlier this year, the Office for National Statistics (ONS) reported that 40% of adults in the UK now use cloud storage services. A certain amount of storage can be obtained for free. But some providers can charged up to £40 per month.
"If our review finds breaches of consumer protection laws, we will take further action to address these," said Nisha Arora, the CMA's senior director for consumer.
That could include "enforcement action using our consumer law powers, seeking voluntary change from the sector, or providing guidance to business or consumers."