Several million Facebook users in the EU who installed the Cambridge Analytica app and their friends may have been affected by the data leak involving the political consultancy.

Facebook said last week that as many as 87 million people might have had their data accessed -- an increase from the 50 million disclosed in previous reports. Facebook is basing the estimate in part on the number of friends each user might have had. Cambridge Analytica said in a statement that it had data for only 30 million people.