Google has previously been accused of abusing its dominant position in web search, and now with the popularity of its Android operating system at an all-time high, it’s facing new accusations that it’s using similar tactics in the mobile market.

As always, the accusations have come from arch rival Microsoft. The Redmond-based firm, along with Oracle, Nokia and 14 other tech companies, has just filed a complaint with the European Commission, accusing Google of establishing a monopoly on the mobile market with its Android system.

Microsoft heads up a coalition of tech firms known as FairSearch, which put out the following statement in relation to its complaint:

“Google is using its Android mobile operating system as a ‘Trojan Horse’ to deceive partners, monopolize the mobile marketplace, and control consumer data. We are asking the Commission to move quickly and decisively to protect competition and innovation in this critical market. Failure to act will only embolden Google to repeat its desktop abuses of dominance as consumers increasingly turn to a mobile platform dominated by Google’s Android operating system.”

Android Dominates Because It’s Free. Except It Isn’t, Quite.

For smartphone developers like Samsung, Sony and HTC, going with Android is an easy choice to make, since these companies don’t have to pay a cent towards it. Contrast that with Microsoft, which charges something like $30 for each device installed with Windows Phone 8, and it’s not difficult to see why Android is by far and away the most popular mobile phone software.

But while Google gives Android away for free, it does come with a catch. In order to have access to Google Play and the thousands of apps available through it, smartphone makers are obliged to install services like Gmail, Maps and YouTube, displaying these prominently on the device’s home screen. Samsung et al can choose to opt out, but if they did so they’d have to create their own app store for customers to use.

Google doesn’t need money for Android, because it already rakes in billions from its advertising profits.  And because most manufacturers go along with its deal and install their apps, each device that’s sold only grows its share of mobile search traffic, further cementing Google’s dominance of online advertising.

But Microsoft and its allies say that this practice is inherently unfair and has allowed Google to develop a monopoly of the mobile web. Their argument is that thanks to its dominance of web search and the advertising revenues that this derives, no one can compete with Android because no one else can afford to develop a new mobile OS and give it away for free.

Does Microsoft’s Complaint Hold Up?

At face value, it does seem that there’s some merit towards Microsoft’s argument. But if we look closer, it’s also true that Google’s dominance of mobile is far from assured. Take Samsung for example, which sells something like 40% of all Android handsets at present. It’s been plowing millions of dollars into the development of its own Tizen operating system and has promised to release the first phones later this year. While Tizen will only run on low-cost handsets to begin with, if they catch on there’s every chance that Samsung could decide to dump Android altogether, and then where would Google be?

There are other threats too. Mozilla’s Firefox phones are set to go on sale sometime this summer, while the Ubuntu phones and tablets we saw at this year’s Mobile World Congress looked absolutely stunning. Along with rumors that Amazon may be about to introduce its own smartphone, and the rise of cheap Chinese-made handsets running unofficial versions of Android, Google is clearly going to have a real fight on its hands to retain its current level of dominance.

Android could even be threatened by the apps it runs – witness Facebook Home and its ability to consume an entire device, effectively relegating Android to the background.

In addition, Microsoft’s argument that it can’t afford to give Windows Phone 8 away for free doesn’t really hold much water – let’s be honest, regardless of how Microsoft derives its revenues, they’re on a similar scale to Google’s, and so if Android can be given away why not Windows Phone?

As we know too well, Microsoft is hardly the most innocent of parties anyway. It used similar tactics years ago with Windows to kill off competing browsers and office suites, and authorities in the US and Europe quite rightly took action to prevent this.

But then again, Google doesn’t exactly have the best track record in this department either, and so any accusations against it need to be looked at. Moreover, few people know the real terms that Google dictates to smartphone makers, and if they are being unreasonable in their demands then they should definitely be stopped. It’s not clear whether the European Commission will investigate the FairSearch charges, but really it should. Just because Microsoft has been guilty of similar practices is no reason not to investigate.