Stripe records user movements on its customers' websites

Stripe cofounder here. The question raised ("Is Stripe collecting this data for advertising?") can be readily answered in the negative. This data has never been, would never be, and will never be sold/rented/etc. to advertisers.

Stripe.js collects this data only for fraud prevention -- it helps us detect bots who try to defraud businesses that use Stripe. (CAPTCHAs use similar techniques but result in more UI friction.) Stripe.js is part of the ML stack that helps us stop literally millions of fraudulent payments per day and techniques like this help us block fraud more effectively than almost anything else on the market. Businesses that use Stripe would lose a lot more money if it didn't exist. We see this directly: some businesses don't use Stripe.js and they are often suddenly and unpleasantly surprised when attacked by sophisticated fraud rings.

If you don't want to use Stripe.js, you definitely don't have to (or you can include it only on a minimal checkout page) -- it just depends how much PCI burden and fraud risk you'd like to take on.

We will immediately clarify the ToS language that makes this ambiguous. We'll also put up a clearer page about Stripe.js's fraud prevention.

(Updated to add: further down in this thread, fillskills writes[1]: "As someone who saw this first hand, Stripe’s fraud detection really works. Fraudulent transactions went down from ~2% to under 0.5% on hundreds of thousands of transactions per month. And it very likely saved our business at a very critical phase." This is what we're aiming for (and up against) with Stripe Radar and Stripe.js, and why we work on these technologies.)

[1] https://news.ycombinator.com/item?id=22938141

Here's hoping it also reduces the exorbitant amount of false positives we've been seeing with Stripe's fraud prevention services, which cost us a lot in lost legitimate sales.

I'm sorry to hear that! Feel free to email me (patrick@stripe.com) and I'll connect you with the team if you'd like us to do a deeper dive.

But, yes, part of the intent here is to enable us to achieve better ROC[1] in our models and to block more fraud while also encumbering fewer false positives. From our testing, it's very clear that these bot-detection techniques do substantially improve the accuracy when compared to other, coarser heuristics.

[1] https://en.wikipedia.org/wiki/Receiver_operating_characteris...

A user shouldn't have to email a cofounder to get in touch with a team member. The last time I integrated stripe on a site as a final test before it went live I had my cousin make a purchase and the site got flag as potential money laundering because we had the same last name. At the time literally zero customer service. It took 8 years before stripe started doing any customer support. Cool launch pages but personally I'll never use stripe again