Households could be reaching their download limits without realising, according to one expert.
Michael Phillips, Product Director at Broadband Choices, has told Web User that broadband subscribers may not be aware of how much bandwidth is being swallowed by their kids.
Mr Phillips said that some applications on social networking sites such as Facebook can use up data allowances or mean connections are slowed due to fair usage policies.
He said: "Another issue is where more than one person uses the same broadband connection.
"For example, parents need to be aware of how much their children are downloading to avoid the shock of a bumper usage bill at the end of the month."
The broadband expert was speaking in the wake of the news that the BBC iso bring out an HD iPlayer, which is expected to use up data at a much faster rate than the present version.