After holding out against the wishes of the World Wide Web Consortium (W3C) and online advertisers for almost three years, Microsoft has given in to the pressure by disabling default 'Do Not Track' settings for new installations of its web browsers.

The move brings Internet Explorer and Microsoft's future Spartan browser into line with rivals Firefox and Chrome, both of which require users to specifically enable Do Not Track settings.

But W3C's insistence against Do Not Track by default continues to puzzle industry analysts and privacy advocates alike.

"I'm frankly scratching my head on why W3C is so firm on this," Constellation Research principal analyst Steve Wilson told Information Age.

"W3C should have a privacy-positive default - period."

Do Not Track is a browser feature that - according to Mozilla's definition - lets a user "express a preference" not to be tracked by websites. The preference doesn't have to be honoured - and many web services ignore it when serving up content.

Despite their propensity to ignore Do Not Track signals broadcast from browsers anyway, online advertisers have taken a particularly hard line against default Do Not Track settings.

Default settings, the argument goes, make it harder to know whether the user is against tracking or simply didn't untick a box when they set the browser up.

Microsoft, it seems, no longer wants to be seen as providing an excuse for advertisers to ignore Do Not Track.

"Websites that receive a Do Not Track signal [from our browsers] ... could argue that it doesn't reflect the users' preference, and therefore, choose not to honour it," Microsoft's chief privacy officer Brendon Lynch said.

Wilson, however, doesn't buy into the idea that Microsoft, through its support of a default Do Not Track setting, was a roadblock to the mechanism's rollout or effectiveness.

"I would say that W3C is the block," he said.

"Everybody says in line number one of their privacy policies that 'We respect your privacy'.

"Any advertiser or web service that claims to be privacy-respectful wouldn't track [user activities] anyway."

Why now?

While W3C has been against Microsoft's position on Do Not Track for some time, it appears a recent "refinement" to the consortium's draft industry-wide Do Not Track standard forced Microsoft to change its tune.

In a blog post, Microsoft quoted the following passage from the draft text:

Key to that notion of expression is that the [Do Not Track] signal sent [by the browser] MUST reflect the user's preference, not the choice of some vendor, institution, site, or network-imposed mechanism outside the user's control; this applies equally to both the general preference and exceptions. The basic principle is that a tracking preference expression is only transmitted when it reflects a deliberate choice by the user. In the absence of user choice, there is no tracking preference expressed.

"Put simply, we are updating our approach to Do Not Track to eliminate any misunderstanding about whether our chosen implementation will comply with the W3C standard," Lynch said.

Does it matter?

Whether Do Not Track is or isn't enabled by default in the browser might not be enough to make it useful to internet users.

Privacy advocate and Xamax Consultancy principal Roger Clarke told Information Age that he was "extremely cynical" about the Do Not Track scheme.

"The simple fact is it's a self regulatory mechanism that's been devised by American corporations in order to avoid regulation, and it's certainly not been designed to provide the kinds of protections that consumers need," Clarke said.

"An industry-designed scheme is never going to be effective to protect consumers".

Clarke said the fact that complying with Do Not Track requests was optional, combined with confusion over how it works and how to switch it on, made the scheme "ineffective" and "toothless".

"You put those things together and it's a nothing [scheme]," he said.

"I can basically just shrug my shoulders at the Microsoft announcement on the basis of, 'So what?'

"We had something that was worth about 15 to 20 percent of what consumers need, and we just lost a few more of those percentage points [of usefulness]. Shrug of shoulders."

Should government intervene?

Clarke notes that the Australian Government has previously tackled telemarketers - via Do Not Call - and spam, via the Spam Act.

"These are a couple of the few stand out pieces of legislation of a consumer-protective nature in the last few decades in the electronic space," he said.

He believed there were few - if any - reasons why the Australian Government could not step in and regulate to make Do Not Track more useful to consumers.

"Do Not Track is not easy but neither is spam," Clarke said.

"If there's a concerted effort by government and government agencies - supported obviously by industry associations and consumer advocacy organisations - it would be feasible to come up with a sensible form of regulation."