The security of the UK's biggest internet service providers needs "major improvement", according to one expert.
Security consultant Paul Moore examined the publicly available information of the UK's six biggest ISPs.
He said he found plenty of bugs that could be exploited by hackers.
But he said most ISPs had been in contact with him and had worked to tighten security once told of the issues.
The audit of TalkTalk, Sky, BT, Plusnet, EE and Virgin Media was kicked off in the wake of the TalkTalk hack, which saw the personal details of 157,000 of its customers exposed.
More than 15,600 bank account number and sort codes were stolen.
Similar problems to those encountered by TalkTalk could have been experienced by any of the major ISPs, Mr Moore believes.
"There have been a couple of incidents where I had to contact ISPs to report things that were serious," he told the BBC.