In a case that began in Spain, Google is now before the European Court of Justice, which could force the search giant to delete information that breaches a person's privacy.
In the Spanish case, a man complained when he searched Google for his name and found a years-old news article reporting his property would be auctioned because he failed to make his social security tax contributions.
Spanish authorities argued Google, when it operates in Spain, should be required to remove such information if it is believed to be a breach of an individual's privacy.
Google's response was that it should not have to delete the search result because the company didn't create the article in the first place. Rather, it is the original publisher's responsibility, and that its search engine does not "publish" but is merely a channel for content created by others.
When a Spanish court upheld the man's complaint and ordered Google to delete the information, Google challenged the ruling, setting the stage for the European Court of Justice to consider the matter.
The court's ruling will be seen as a test of a draft European law, proposed by the European Commission in 2012 and being debated by the European Parliament, that would give people "the right to be forgotten" -- in other words, the right to have personal data deleted, especially from websites.
Following a hearing in Luxembourg last week, a court advocate-general will publish an opinion on the matter June 25, and the judges are expected to rule by the end of the year.
The court will also likely address the issue of whether a search engine run by a company based in the United States can be subject to EU privacy law.
U.S. officials have warned of consequences if the "right to be forgotten" draft law receives final approval in Europe.
Such a law could bring on a trans-Atlantic "trade war," John Rodgers, an economic officer in the U.S. Foreign Service, said earlier this month at a conference in Berlin.
There is no "fundamental right to data protection," Rodgers said, and "things could really explode" if the EU enshrines the right to be forgotten in law.
The law would apply to all 27 EU member states, but companies that process personal data of EU citizens from outside the borders of the trading bloc -- as Google does from the United States -- could also be subject to the rules, the European Commission argues
"As long as a company offers its goods or services to consumers on the EU territory, EU law must apply," a commission spokesperson said.
At the heart of the issue is a basic conflict between Europe's data protection and privacy laws -- among the strongest in the world -- and U.S. laws on free speech and expression -- also among the strongest in the world.
The "right to be forgotten" should not result in data being removed or manipulated at the expense of freedom of speech, U.S. Web companies have said, and allowing privacy laws to trump freedom of speech would result in "a form of censorship," lawyers for Google said in arguing the Spanish case.
With so much at stake, people on both sides of the Atlantic will be watching closely to see what the European Court of Justice decides.