Facebook has launched an appeal against the £500,000 fine it was given following the Cambridge Analytica scandal.
The social network says that the penalty handed out by the ICO last month was unfair, as there was "no evidence" that user information was shared inappropriately.
Facebook says that because the watchdog found no evidence that the personal data of UK users was shared without their knowledge, the fine (the maximum value allowed by law) was unjustified.
Around a million Facebook users in the UK are thought to have had their account information unlawfully accessed by agents working for Cambridge Analytica. User information was directly harvested using a free personality quiz on the site, with the public data of their contacts also recorded.
The ICO has noted that Facebook could have faced a much higher fine that £500,000 if the case had taken place under GDPR, which only came into force following the supposed data collection.
"Their reasoning challenges some of the basic principles of how people should be allowed to share information online, with implications which go far beyond just Facebook, which is why we have chosen to appeal," a statement from Facebook's lawyer Anna Benckert said.
"For example, under the ICO's theory people should not be allowed to forward an email or message without having agreement from each person on the original thread.
"These are things done by millions of people every day on services across the internet, which is why we believe the ICO's decision raises important questions of principle for everyone online which should be considered by an impartial court based on all the relevant evidence."
The ICO has confirmed it has received Facebook's appeal, which will now be considered by the independent General Regulatory Chamber tribunal.
If Facebook is unhappy with the outcome of the tribunal, it can take its case to the UK Court of Appeal.
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