The feds had to go to court to force Facebook to cooperate with tax probe

The US Justice Department went to court to force Facebook to cooperate with the Internal Revenue Service in a tax probe, according to a petition filed on Wednesday in San Francisco. 

Since 2010, the IRS has been investigating whether Facebook understated assets by "billions of dollars" when it transferred part of its business to an Irish subsidiary. 

Facebook was supposed to provide the IRS with additional books, records, papers, and other data as part of the examination by June 17, but failed to do so. 

So, the feds are taking the issue to court, asking for an order to force Facebook to provide the information. 

"Facebook complies with all applicable rules and regulations in the countries where we operate," a Facebook spokesperson said in a statement. 

Here's the full filing: