Every few years, I buy from newegg.com. Every time my CC company flags and declines it and I have to call to clear it.
I rarely travel, perhaps a flight every few years. My card gets swiped at the airport check-in and the next day I see 10,000 in flight charges. I call and tell them they are fraudulent charges. I have to fight with them for weeks to get the charges removed.
I personally would like an app where charges over $500 require a 2-stage authorization. Just ping me and I'll be the final call, they can't decide what's fraudulent or not on their own.