More than a year ago, in a decision that stunned many American Internet companies, Europe’s highest court ruled that search engines were required to grant an unusual right — the “right to be forgotten.” Privacy advocates cheered the decision by the European Court of Justice, which seemed to offer citizens some recourse to what had become a growing menace of modern life: The Internet never forgets, and, in its robotic zeal to collect and organize every scrap of data about everyone, it was beginning to wreak havoc on personal privacy.

Under the ruling, Europeans who felt they were being misrepresented by search results that were no longer accurate or relevant — for instance, information about old financial matters, or misdeeds committed as a minor — could ask search engines like Google to delink the material. If the request was approved, the information would remain online at the original site, but would no longer come up under certain search engine queries.

Search engines and free speech advocates, calling the ruling vague and overbroad, warned of dire consequences for free expression and the historical record if the right to be forgotten was widely enacted. Now, they say, their fears are being realized.

Recent developments — including a French regulator’s order that all of Google’s sites, including American versions, should grant the right to be forgotten — suggest the new right may not end with Europe. Under the banner of privacy, some free-speech watchdogs say, a huge and unwieldy eraser is coming for Google results across the globe — even the ones in the United States.