I didn’t know that either and have tried the iOS App once but did not upload anything to them, I just wanted to see what the App could do/how it feels like. Then I read their Privacy Police and ToS and did some searching. I very quickly decided that this is not a service I’d want to use.
So I send them a GDPR request demanding the deletion of my account and all associated data.
I had to send them a very stern email threatening legal action and mentioning some personal contacts I have to some federal law enforcement officer who works privacy cases to even get an answer that was more than ‘please use our privacy center to delete your data/account’.
Finally I got back some generic email stating that all my data was deleted. Some canned response thing though. I highly suspect that they still have my data on their system.
I highly suggest not to use the service of FullContact!
Start here? ;-)
>> mentioning some personal contacts I have to some federal law enforcement officer who works privacy cases