The smartphones of shoppers being tracked in a store
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What price for free wi-fi?

Smartphone users are always looking for free wi-fi but at what price does it come? Businesses are looking at ways to make the free wi-fi they offer work for them too. It can track our movements through our phones and reveal a great deal about us to those who have something to sell.

BBC Click's Spencer Kelly reports.

Watch more clips on the Click website. If you are in the UK you can watch the whole programme on BBC iPlayer.

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