On July 22 Spain passed a law (link in Spanish) called the canon AEDE, after the acronym for Spain’s daily newspapers’ association. The law has been dubbed the tasa Google (“Google tax”) in the Spanish press and gives these publishers the right to seek payment from any site that links to their content with a “meaningful” description of the work.

Though the government hastened to clarify (Spanish) that the law won’t apply to social networks like Twitter and Facebook, what it means for search engines such as Google and sites like Digg or Reddit—or even Quartz—is still quite unclear. What’s a “meaningful” description? How much compensation is due per link? Who arbitrates in the event of a dispute? And in a world where every news outlet writes the same story, what is exclusive content? The fine for violation of the law is as much as €300,000 (Spanish) and one study says it would cost internet firms €1.13 billion euros (Spanish).

The law has invited criticism from internet entrepreneurs who fear it will stifle innovation, since so many new web businesses depend on linking in some form; from magazines and digital outlets that aren’t members of AEDE and won’t be able to claim compensation; and of course from Google itself, which protested on its Spanish blog in February that Google News doesn’t carry ads, and noted that publishers can easily remove themselves from search results at any time. (Every website has a file called robots.txt that can instruct search engines not to index it.) That, of course, the publishers don’t want to do, since without Google’s links they would lose a huge number of readers.

But Spain is not the first European country to try to force Google to pay them instead. Germany passed a similar law last year, which will soon be put to the test: Several of Germany’s major publishers last month demanded Google pay them 11% of its revenue from linking to their content. (What they’ll demand from ad-free Google News isn’t clear.) Google has also resolved copyright disputes over linking with both French and francophone Belgian news publishers by funneling more money their way.

The fact that Spain’s law protects only its daily newspapers and not other publishers may make it harder to defend, but now that it has passed, we’ll have to wait for the first test cases. How they’ll be enforced is still unclear, but it’s worth remembering that Spain gave us the case that led to another controversial ruling that went against Google: the “right to be forgotten.”