WIRED.com reports that Facebook employs Mac Mini farms in its data centres.

Facebook’s iOS app is so complex — designed to run on so many mobile devices across the world, and built with code written by so many Facebook engineers — that the company needs an enormous network of machines to test it. “We run hundreds of thousands of tests every couple of hours,” says Christian Legnitto, the ex-Apple man who oversees the Facebook engineering team responsible for the final release of the company’s mobile apps. “When you’re shipping [an app] to hundreds of millions of users, those one-in-a-million bugs can happen hundreds of times.”

But because Apple insists that all Apple software run on Apple machines, Facebook can’t test its iOS app on the Linux servers that drive the rest of its empire — or on the popular cloud services offered by tech giants like Amazon or Microsoft. So, says Legnitto, the company operates “racks and racks” of Mac Minis that run Apple’s Mac OS X operating system.

Last week, I reported on Google using 40,000 Macs.

The issue of government spying has been in the spotlight ever since Edward Snowden’s exposé. Now several major tech companies are banding together at reformgovernmentsurveillance.com to call for the reform of government surveillance. We’re talking about heavy hitters, Apple, Microsoft, Facebook, Google, AOL, LinkedIn, Twitter, and Yahoo.

The principles that they’re calling for include:

• Limiting Governments’ Authority to Collect Users’ Information

• Oversight and Accountability

• Transparency About Government Demands

• Respecting the Free Flow of Information

• Avoiding Conflicts Among Governments

There isn’t any promise that the government will listen and implement any recommendations from these companies, but they have a much larger voice than the average privacy advocate on the street, so hopefully their collective voice (and clout) will count for something.

Eight Big Tech Companies Demand That The Government Changes How It Spies And Handles User Data

WIRED UK reports that Microsoft has designed a smart bra to combat emotional eating.

But the team wanted to have a system of wearable sensors that measure electrodermal activity (EDA), which is essentially the amount of sweat on a person’s skin; and electrocardiogram (EKG) data. Both are useful for gauging emotions.

Wearable devices that know you inside out.

Back in October, the modular Project Ara phone caused quite a stir. The concept of a modular phone which will allow users to upgrade different parts of the phone is certainly attractive. While it was more akin to a concept back then, it now seems that Motorola is actually putting some serious effort into the concept, possibly turning it into a reality sometime in the near future.

In a recent interview, Motorola CEO Dennis Woodside hinting that they’re close to completing an actual prototype of such as phone. Of course, a prototype isn’t a promise that a mass market version will be produced anytime soon, but it’s definitely a step in the right direction.

Even though the concept itself is good, I do have some serious concerns if it’ll actually be popular. In the PC market, there are many PCs that are assembled by hobbyists, but the combination of readily available parts isn’t always something that most consumers are looking for. When discussing finesse, it’s pretty noticeable that integrated machines such as Apple’s Macs and well-designed PCs from manufacturers such as Dell have an edge over a PC assembled at home. There are pros and cons to either solution, but it remains to be seen if a modular phone will really catch on. On a personal level, I’m looking forward to actually being able to fiddle with a modular phone, so hopefully Motorola will be able to pull it off.

Modular Project Ara smartphone prototype not too far off, says Motorola

“There is a [Project Ara] prototype and it is pretty close,” Motorola’s CEO said. “The idea is you have a skeleton that holds together a set of components and the components slide in and out. If we have the interfaces and the protocols that enable the speaker to speak directly to the CPU then this would all be possible.”

Woodside said the biggest obstacle for Project Ara was making components universally work with each other. Since most components are made for a specific device and its design, making them interchangeable is a struggle. So Motorola is trying to make an open platform.

The team behind the Square Reader have a keen eye for detail, so it’s no surprise that a lot of thought went into the redesigned Square Reader.

How Apple’s Lightning-Plug Guru Reinvented Square’s Card Reader

The friction felt when a user swipes their card is a good example of how the team kept an eye on the fine points of the device.

The redesign also gave Dorogusker and company a chance to tweak the feel of the swipe itself, which is a crucial detail that makes the product itself feel trustworthy despite its tininess. By tweaking the design of the spring to which the magnetic read head was attached, the team was able to fine-tune the friction customers feel when swiping their card. At one point in development, they found that the level of contact they needed to successfully transfer data from a card resulted in a swipe that felt too loose. And when the swipe felt too loose, it felt like it wasn’t working, and would thus require another swipe. So they increased the friction above what was actually needed–an adjustment that was overkill from a technical point of view but resulted in a swipe that felt perfect to the hand.

One of the greatest improvements in the new Square Reader is that it doesn’t require a battery to operate anymore. Simplifying the device, and removing an additional point of failure.

In terms of the design of the internals, though, the chip offered another fantastic advantage: an opportunity to ditch the Reader’s battery. The old version relied on a coin cell, which added around two millimeters to the overall thickness of the device. With their own chip, though, Square was able to be much more efficient in their use of power, to the point that they could draw all they needed from the smartphone via the audio jack. As a result, the new Reader dropped the battery and two millimeters along with it. “For the nerds on the team, that is crazy awesome,” Dorogusker says.

Reuters reports that Twitter is tying up with Singapore-based startup U2opia Mobile make its services available on mobile phones without Internet.

U2opia Mobile, which has a similar tie-up with Facebook Inc, will launch its Twitter service in the first quarter of next year, Chief Executive and Co-founder Sumesh Menon told Reuters.

Users will need to dial a simple code to get a feed of the popular trending topics on Twitter, he said.

More than 11 million people use U2opia’s Fonetwish service, which helps access Facebook and Google Talk on mobile without a data connection.

Twitter SMS commands.

Twitter seems to have come to a full circle since it was initially created as an SMS service to communicate with a small group.