The European Union is set to unveil new rules it says will "overhaul" the digital market, including how tech giants operate.
A pair of laws - the Digital Services and Digital Markets Acts - will be announced later on Tuesday.
They are expected to be the biggest revision in 20 years, focusing on competition and making platforms responsible for hosted content.
There are also likely to create heavy fines for violations of the rules.
The rules are being spearheaded by commissioners Margrethe Vestager and Thierry Breton, both of whom have a history of strong rhetoric against the biggest tech giants - as commissioners for competition and the internal market respectively.
Writing a joint opinion piece for The Irish Times on Sunday, the pair hinted at the tone of the proposals: "The business and political interests of a handful of companies should not dictate our future.
"Our rules on digital services in Europe - the most coveted single market in the world - date back to 2000. Most online platforms hardly existed back then," they wrote.
"We need to update our toolbox and make sure that our rules and principles are respected everywhere. Online as well as offline."
One key part of the legislation is expected to address the dominance of big players such as Google and Facebook - which tend to be US-based.
In particular, the European Commission has indicated it objects to such giants using the data they gather from one service to "improve or develop" a new one in a different area, making it difficult to compete with them.
The Commission labels such firms "gatekeepers", saying they "set the rules of the game for their users and their competitors".
Technology analyst Benedict Evans said the new rules are likely to have "unintended consequences".
"California thought Uber drivers should be classed as employees, which we can debate, but passed a law that accidentally banned all freelance work," he said, referencing the years-long controversy over worker's rights in the state, which was only settled by popular vote last month.
"GDPR aimed to protect privacy, but also strengthened Google and Facebook and weakened independent media," Mr Evans added. Smaller media outlets have found it difficult to comply with the privacy, leading many US outlets to simply not allow EU readers on their sites.
He said he expected the new acts to "probably contain sensible things, contentious things, and silly things".