Back in the old days, the big bad company in tech that all the other companies teamed-up against was Microsoft. 

Microsoft was the evil empire.

So, Apple and Google worked together to squash Microsoft.

Former Apple CEO Steve Jobs used to mentor Google cofounders Larry Page and Sergey Brin. Google CEO Eric Schmidt used to sit on the Apple board.

This is no longer the case. 

These days, the common enemy is Google.

In recent years, there have been a number of explicit and implicit partnerships between the three biggest companies in consumer technology — Apple, Microsoft, and Facebook.

Some examples:

• Microsoft invested in Facebook at a $15 billion valuation back in 2007.

• Facebook generates massive ad revenues through its iOS app. Conceivably, Apple could ask for a piece of that business. It has not.

• Apple has integrated Facebook deeply into iOS.

• Microsoft powers Apple's Siri. All those Siri queries are improving Microsoft's machine-learning capabilities versus Google's.

• After first buying it for $6.3 billion in in 2007, Microsoft sold its ad-serving platform, Atlas, to Facebook in 2013 for peanuts. Now Atlas is at the center of Facebook's rapidly growing ad stack. 

• Microsoft and Apple co-lead a group of companies that outbid Google for mobile patents from Nortel. This forced Google buy Motorola for $12 billion.

All this ganging-up against Google is coming during a rough transition period for the company.

• CEO Larry Page, frustrated with the pace of innovation at the company, recently took a big step back from day-to-day operations, turning over control to Sundar Pichai.

• Search advertising is the best way to make money on the web. But people aren't using the web as much on their mobile phones as they did on their desktops. Google ad revenues aren't growing like they used to.

• People are increasingly searching for products on Amazon, rather than using Google. 

• The executive in charge of running the moneymaking side of Google, Nikesh Arora, left for a new job at Softbank.

• The EU wants to break up Google, which it views as a parasitic American company. 

• Facebook has decided to compete with YouTube for video-advertising dollars, and Facebook may win.