Beware of broadband installation guys. Got a credible proof today that they are doing something fishy with WiFi access password. Make sure to change the WiFi access password the moment anyone of them access the router configuration page. Change default router password also so that they cannot access router page without you knowing it. Never leave them near an unlocked system ever. Those systems can be used to access WiFi router page using default passwords.
This also blows the lid on the media stories about terrorists using unprotected WiFi. They can use protected WiFi also if the broadband guys tell them password.
It happened with Airtel who have outsourced everything to vendors including installation. The way he accessed my WiFi password was more than suspicious activity. And the guy accessed my existing BSNL router page when he had business doing it. I opened router page thinking he needed to check router settings. He never did that. Instead he checked WiFi access password & closed router page.