They link up with your bank account and generate as many virtual cards as you want that are locked to the first vendor you use them on so if say McDonald’s get their card data stolen it won’t be able to charge the card for anything other than McDonald’s.
They also make their money from the card fees so they manage to be both free and not sell your data.
https://privacy.com/ I’ve been using them for around 6 years now.
They link up with your bank account and generate as many virtual cards as you want that are locked to the first vendor you use them on so if say McDonald’s get their card data stolen it won’t be able to charge the card for anything other than McDonald’s.
They also make their money from the card fees so they manage to be both free and not sell your data.