"There were people like me saying it could go to data brokers, I think it was a risk they were willing to take."
Facebook took a light touch approach to ensuring data was used in the way developers said it would be, Parakilas told the Department of Digital, Culture, Media and Sport Committee.
He said in his time at Facebook, between 2011 and 2012, no external developers, who were granted Facebook user data to develop apps, were audited about whether they used data in line with their agreements with Facebook. However, several were banned from the platform or sued as a result of press reports. Facebook last week banned Cambridge Analytica for abusing its developer rules.
"During my experience, I don't remember a single, physical audit of a developer's storage. There were only a handful of lawsuits and bans," he added.
MPs slammed Facebook's lack of oversight of developers who were able to access user profile information. Damian Collins, chair of the DCMS committee, said Facebook "turned a blind eye because they didn't want to find out the truth".
It was Facebook's data sharing policies that allowed UK company Cambridge Analytica and others to harvest user data, although the way Cambridge Analytica contractors used this data was against its rules, Facebook has said. Until 2015, Facebook allowed apps to harvest information about users who gave permission, as well as their friends who did not.
Earlier today, the academic at the centre of the Cambridge Analytica scandal, Aleksandr Kogan, told BBC Radio 4 "tens of thousands" of apps had done the same thing. Kogan said: "My view is that I'm being basically used as a scapegoat by both Facebook and Cambridge Analytica when... we thought we were doing something that was really normal."
Facebook said earlier this week it remains "committed to vigorously enforcing our policies to protect people's information".
Facebook is only just realising the problems its platform creates, Parakilas says.
"If they realised the enormity of the problems [with Facebook apps] they would have taken some action. I believe they are now starting to see this," he said.
However, while Facebook data was allegedly misused by Cambridge Analytica, it's not clear what impact exactly it had on the US election. In secretly recorded footage by Channel 4 News, Cambridge Analytica claims it had a major impact on the election result, but others have dismissed the power of their advert targeting.
That said, what Parakilas has said suggests that many hundreds more apps than most people were previously aware of have access to their Facebook data, and Facebook has done little to ensure that data is not misused.
