Siri, the voice-controlled intelligent assistant, has succeeded in endearing itself to Apple fans, prompting the iPhone 4S to become the best selling iPhone ever. However, even as the users enjoy interacting with their virtual assistant, Siri is being blamed for being a data hog.

A study from mobile network management company Arieso revealed that iPhone 4S devours nearly three times date than iPhone 3GS, and as much as twice the data than iPhone 4. And, Siri, the personal assistant exclusive to iPhone 4S, has become the scapegoat.

No doubt, Siri can can do almost anything for its master after receiving the voice command, including placing phone calls, sending messages, scheduling meetings, finding nearest restaurant, and more. However, it requires regular connections with Apple servers and the Web, making it more likely to eat up a lot of data, Arieso's Chief Technology Officer Michael Flanagan told Bloomberg.

Siri also has a partner-in-crime - iCloud - which is also being accused of being a major data eater by Flanagan. Apparently, cloud storage has become one the most popular applications on smartphones and tablets and more and more manufacturers are now packing the technology into their device to catch up with the tech trend and, consequently, more and more data are required.

Except the iPhone family, heavy data consumers also include Samsung’s Galaxy S and S II, the Nexus One and HTC Desire S. According to Arieso, Samsung Galaxy S devoured 199% more downlink data than iPhone 3G and, HTC's Desire S uses almost the same amount of data as iPhone 4S and as much as three times of iPhone 3GS' data usage.

Not surprisingly, the wireless carriers are facing the immense challenge of improving their network. Many carriers, such as AT&T and Verizon, are also trying to put a cap on how much data the subscribers can consume every month with the tiered data plans. If they overuse the data, they will be heavily charged for the excess data consumed.

And though the tiered data plans are being criticized by the customers, the carriers are reluctant to remove them as they claim that the plans are designed to improve the quality of the networks and make the subscribers use data more responsibly or else, it may cause a network outage.

Arieso's study supports the carriers' claim - it showed that a minority of customers were the 'extreme' or heavy data users. More specifically, only 1% subscribers use half of all downloaded data, and 3% of subscribers download nearly 80% of all data, according to Flanagan.

The introduction of increasingly sophisticated devices, coupled with growing consumer demand, is creating unrelenting pressure on mobile networks. The capacity crunch is still a very real threat for mobile operators, and it looks set to only get harder in 2012, Flanagan said in the study. The mobile industry needs new investment and new approaches to boost network performance and manage the customer experience.

And how will be future networks handle this problem? What I predict is that we in the future will see increasingly personalized deployments of networks … where the placement of some base stations are driven by the most extreme users, Flanagan added.