Online taxi-hailing firm Uber is planning to increase its security team from 25 to over 100 employees by the end of the year.

The company is facing an increasing number of security threats associated to data privacy, hacking and the safety of its offices and employees.

In February this year, an anonymous hacker managed to access the personal data of about 50,000 Uber drivers.

Uber chief security officer Joe Sullivan was quoted by the Financial Times as saying employees may need to be protected as they could be polarising figures in their communities.

Sullivan said the company was working on identifiyng who had access to customer data, for how long and for what purpose.

Earlier this month, Uber closed a new round of funding, pushing its value to around $51bn.

Microsoft and the investment arm of Indian media firm Bennett Coleman & Co. are among the companies that have participated in the funding round.

Last month, Uber was fined $7.3m for hiding information from California Regulators.

Some of the unshared files include reports on causes of accidents, drivers turning down journey requests and the amount of disabled access cars available.