I can't say whether the description of the method is accurate, but I want this story to be true:
https://www.reddit.com/r/ParlerWatch.../?context=1000
All the URL:s that were used:
Twitter Link
They claim to have archived 70TB worth of data, including videos and personal information (eg. driver's license). The FBI may already have had access to this data and perhaps that helped them set up the no fly lists so quickly.