Facebook is very protective of its users' privacy and personal data despite the use of personalised advertisements, the firm's chief operating officer Sheryl Sandberg has said .
The businesswoman said Facebook users retain control of their data and personalised adverts do not compromise them.
In an interview with BBC Breakfast, she said: "Privacy is of the utmost concern and importance to Facebook and it's important to us that the people who use our service know that we are very protective of them. It is their data, they have control of it, they share it.
"When we are able to personalise ads, we are doing that without sharing their private data with any advertisers."
Her comments follow the launch of the UK and Ireland SMB Council at the company's international headquarters in Dublin, which aims to increase participation between Facebook and small to medium-sized businesses.
Mrs Sandberg said working with small to medium-sized businesses was important because "o ur missions are inextricably tied and the challenge and the opportunity of this huge technological shift that we're going through is one that we can work together (on).
"We have 25 million small to medium-sized businesses around the world that use our free products to set up a page and use it to reach their customers. So just as I can share with you if we're friends on Facebook, small businesses can reach their customers."
The sixth most powerful woman in the world, according to Forbes magazine last May, said: "We are in the middle of the fastest adoption of disruptive technology the world has ever seen. The word 'online' is becoming an old-fashioned word because we're all going to be connected all the time."
Mrs Sandberg also wrote and published Lean In last March, which advised women on how to be more confident and successful at work by becoming more involved and to face their fears.
But she said there was still more to be done: "D espite all the progress women have made, men still have the great majority of the leadership positions in every business, in every industry, in every country in the world. It's really important that since women make up half the population, women start having half the seats at tables where decisions are made, and that's not where we are today."
She said that women thinking about doing something should ask themselves what they would do if they were not afraid and then do it.