Companies are registered at the state level, but names are trademarks that are overseen at the federal level. The real Stripe could probably sue and force a change of name due to trademark infringement, especially since the fake Stripe's primary business seems to be online as well. The real Stripe probably couldn't sue and force a change if someone registered another Stripe, Inc. in a different state who paints lines on roads or something.
Being online isn't a business. stripe.ian.sh does not compete with stripe.com, and there's zero risk of consumer confusion between these two websites. Stripe.com has no case for trademark infringement.
If I were Stripe.com's legal counsel, I'd have already fired off a C&D. Stripe.ian.sh isn't trying to subvert traffic, but the entire point of this exercise is to show how it's possible to be confused for the real Stripe.com under certain circumstances. It's a fine line and if I were from the real Stripe I wouldn't want to let those sorts of grey areas go unchallenged.
Free speech is a defense for trademark infringement, especially non-commercial speech. Showing how someone could theoretically be confused is not the same as actually being confused. Consumers aren't confused by someone writing an article about a company... that's not trademark infringement. A trademark does not give you rights to prevent people from writing about your company.
Article has screenshots of it intentionally looking like the stripe homepage. Guess that was an older version, and now it's just a blog post, but it has had the exact same look.
