"Big data" is the catchphrase of the day, appearing at each and every tech conference I have attended. China's technology powerhouses are investing billions of dollars annually in mining the massive trove of consumer data, hoping to outgun rivals and cash in on the rising middle class whose behavior is increasingly transparent and traceable in the digital space.

The pursuit for such lucrative data put e-commerce powerhouse Alibaba Group Holding Ltd and courier giant SF Express (Group) Co Ltd on a collision course in early June. The duo fought over the control of consumer data generated through Alibaba's e-commerce platforms and ended data sharing, delaying tens of thousands of parcels, a move which almost sent the market into disarray.

Therefore, I was not surprised when a friend of mine said he had failed to check the status of two boxes of mangoes ordered via Taobao using SF's delivery services, because the conflict had substantially affected shipments of fresh produce.

Thanks to the coordination of the State Post Bureau, the dispute was finally resolved on July 3, with the pair agreeing to continue data sharing. But the incident underpinned the ever-growing red-hot rivalry among China's leading tech players to command and leverage data generated through a host of online behavior.

For companies, it is a thorny task to make smart use of the data to manage operations, predict demand and trim costs. But for consumers, it is an even more pressing issue to guard their privacy in the big data era.

By tracking users across those sites with what the company calls a "unified ID," Alibaba is now able to not only tailor product recommendations to individual users, but also personalize the storefronts they visit according to their browsing and buying habits. So what I get to see when browsing the shopping app might be totally different from that of my friends.

But when you give it a second thought, customized ads promotions based on your age, gender, shopping preference and even credit records are essentially an intrusion into your privacy. Even without making the effort to know your name, by and large, everything about you is out there, leaving computers calculating the odds of your purchasing a limited edition of branded bag.

It equally applies to scenarios such as browsing and sharing posts on WeChat, tipping my preferred freelancers, looking up restaurant reviews on local service provider Dianping and searching for the best route via Baidu Map. At the end of the day, my online behavior only reinforces the machine's self-learning ability until it gets smart enough to know me better than myself.

Last month, executives of Alipay, China's popular e-wallet, told a tech conference in Shanghai that they have teamed up with public security authorities to allow for quick and smooth hotel check-in and check-out services using facial recognition technologies.

Yet the potential surveillance possibilities of the technology still haunt me: now they would know I like to spend weekends in Hangzhou, and I get hungry easily at night because I finished all three Snickers in the mini bar.

Today, our interactions become public by default online, but private by effort.

Concerns over privacy infringement has led to a series of efforts to curb the use of personal data in many countries. For instance, the European Union has also created the notion of a "right to be forgotten" and "data portability", which allows EU residents to request the removal of search results that they feel link to outdated or irrelevant information about themselves on a country-by-country basis.

China is also ramping up its effort in data protection through law enforcement, yet there is still a long way to go. After all, we're on the cusp of a golden age of using data in every field from business to public health. Don't let the privacy backlash hamper such progress.