The world needs to be wary of the rise of tech giants such as Google, Apple, Facebook and Amazon, comparing their powers to those of countries such as China, European Council President Donald Tusk said in Warsaw on Friday.

"In the East, we see the rise of those capable of controlling everyone's behavior, and in the West we've seen the rise of an uncontrolled, spontaneous empire," Tusk said in Warsaw in reference to the companies during a speech marking Constitution Day.

"Our children are dependent on the internet and everyday will become more dependent on it," he added.

The European Union has been in the forefront of efforts to tighten control on how social media companies handle the personal data of consumers, with rules introduced last May giving regulators the power to impose fines of up to 4 percent of global revenue for violations.