The Spanish broadband and telecoms firm is selling anonymized customer data to retail chains and shopping centers, according to confidential information obtained by a sister publication of Handelsblatt. Some say that is still an invasion of privacy.

(Source: dpa) Telefonica is allegedly offering up customer data to retailers.

Telefonica, Germany’s largest wireless carrier based on the number of customers, has been quietly analyzing the movement data of its customers for some time now. In October, the Spanish-owned firm announced its plan to provide business customers with tools to analyze their own data.

According to a confidential presentation obtained by the German business weekly WirtschaftsWoche, Handelsblatt's sister publication, Telefonica is offering to sell anonymized customer information to retail chains and shopping centers. Documents intended for retail managers showed the company had mined specific "insights" about age, gender, origin and movement from its 44 million mobile customers.

It violates German privacy law to sell the data of individual customers to third parties. Telefonica is selling anonymized data sets -- basically demographic information on customers entering stores and retail outlets -- that cannot be traced back to individuals.

Businesses hope to use this data to better plan and run their operations, and to meet consumer expectations and tastes.

Telefonica is the only German mobile operator selling anonymized customer data as a new branch of business. Deutsche Telekom canceled a pilot project on the analysis of customer data last year following privacy protests.

In Germany, public opinion is the greatest challenge to telecommunications companies looking to profit from big data. Citizens have long-standing concerns about spying, a legacy of the Nazi era and Cold War times.

The obtained data was anonymous and already examined and approved by German data protection authorities, according to the presentation. Telefonica's data provides the "most accurate and comprehensive calculation of frequencies for city centers around the clock," it allegedly stated, with opportunities for retailers to glean information about "site planning, advertising and traffic analysis."

Besides data on public spaces and transport such as buses or trains, Telefonica is reportedly also offering "indoor analysis" on how long customers take strolling through stores and stopping at shelves.

The product is allegedly already being tested in retail chains in Spain and Germany.

Such precise movement profiles could stand to make current models of market research obsolete. Data analysis is a lucrative business that the Spanish-owned coming plans to tap worldwide. According to market research firm IDC, the market for big data was worth $125 billion ($136 million) last year.