Everybody has their ups and downs. For most people, it'll be something like “The bus is running late, but at least I found $5 in my pocket this morning.” Of course if you're Google, the scale is a little bit grander.

On the upside, Google announced on Tuesday that it has officially acquired Motorola Mobility (and the more than 17,000 patents that come with it), adding more ammunition to Google's smartphone arsenal. “As a company who made a big, early bet on Android, Motorola has become an incredibly valuable partner to Google,” said Google CEO Larry Page on the company blog.

The technology giant spent $12.5 billion on the deal, but its pockets may be lightening even more if it isn't careful. The European Commission, suspicious that Google is promoting its own products in its search results at the expense of competitors, has issued the company an ultimatum. If Google doesn't propose changes “in a matter of weeks,” the New York Times reports, it could face an antitrust lawsuit. Europe's antitrust fines have been known to be as high as 10 percent of a company's revenue.

If Google doesn't agree to make some changes to its search results, it could end up facing a two-pronged attack, from the European Commission and the U.S. Federal Trade Commission, which has reportedly been working closely with officials in Europe in pursuing its own investigation of the company.

For more on Motorola Mobility, read:

Intellectual Ventures sues Motorola Mobility over patent infringement

IP acquisitions and antitrust

For more on Google's antitrust woes, read:

DOJ and FTC conduct simultaneous antitrust investigations at Google

Google assuredly refutes antitrust allegations at Senate inquiry

FTC brings in a ringer to run Google antitrust investigation