US and European regulators have a watchful eye on Microsoft, after it emerged last week that it would be impossible for other vendors, such as Google and Mozilla, to develop browsers that are competitive with Internet Explorer on Windows RT (Windows 8 on ARM).

Microsoft disclosed last year that development of third-party apps would be limited to Metro on ARM processors. Microsoft leaned on security concerns as its chief reasons for why it was locking down the platform, but that wasn’t enough to prevent developers from complaining.

It is surprising that it took until now for somebody to make a big stink about it, but here we are. At issue is the 2009 decision in which the EU required Microsoft to give users choice of browser when installing Windows, as well as offering a version of Windows without Internet Explorer. Mozilla claims that Microsoft’s locked-down Windows RT violates this ruling.

Microsoft’s in the clear — for now

Not so fast. The European Commission says it is aware of Mozilla’s claim, but the ruling applied to PCs only. This means that if Mozilla wants to push the issue, it will have to argue that tablets are still PCs. That said, there is the possibility that ARM-based PCs could pop up in the future — actually, that’s probably likely — so Microsoft’s going to have to figure out a defense of its position soon.

The US is taking the same “wait and see” attitude. According to TechNewsWorld, the Senate Judiciary Committee does plan to review Microsoft’s browser decision, but called it “preliminary” and said no hearing is scheduled. So while there may be some question as to whether or not Microsoft is running afoul of the law here, it appears for the time being that Redmond is in the clear.

So, is Microsoft really doing anything wrong? I don’t think so. Windows RT is not Windows, and really isn’t intended for PCs but devices, where other companies have similarly strict app requirements. Look at Apple, it does the same thing in keeping a lot of apps out of iOS. Microsoft is doing the same, and in both cases it has a lot to do with security.

It’s all about security

Browser vulnerabilities are the most common way attackers gain access. When code for these apps are more tight, there are less holes for the hacker to exploit. The browsers in these mobile platforms are more tightly linked to the OS itself. Device operating systems are very strict in who they let in to certain processes — regardless of whether its iOS, Android, Windows Phone, etc. — and that’s a good thing.

While it is disappointing that we cannot select our own browser with modern mobile operating systems, in reality we’re much better off. The attack vectors are limited and if somebody’s getting in, it’s the platform’s fault. The evidence has shown that the tighter the control on the ecosystem itself, the less of a chance of malicious attack. Just look at the difference between Android and iOS when it comes to malware.

Android’s much more lenient app rules have allowed attackers to exploit the OS much more frequently then they have on the iOS platform. But even there, Google has clamped down on some sections of the code in an attempt to protect you the user. Then above and beyond security, the device market is nothing like the PC industry.

In mobile devices, you have something called choice. Don’t like one platform and its rules? There’s plenty of others to choose from. It’s not like you’ll ever be forced to use a Windows RT device — and heck, if you really want to use a different browser, there’ll be plenty of low-power x86 Windows 8 tablets anyway.