Less true now than it used to be, they implemented a limitation after that article was published.

Nowadays, if you try to check someone's salary, there is a big box on the website saying "The person you want to check the salary of will be notified that you checked. Do you want to proceed?" where I believe most people go "Nope, cancel that."

Or you just find someone as a proxy and run all of your queries through them. Like, my grandma in the other end of the country. The other party can't do anything with this information.