Many smartphones and tablets are preset to find and join networks automatically. This may seem like a good idea as it could save you on data fees, but be careful.
Many public networks are unsecure and can easily be breached by hackers.
You can solve this problem in two ways.
First, turn off the option on your device(s) to automatically connect to networks and turn on the option to ask you first. Second, simply make sure your phone or tablet is off when you’re not using it. Hackers can’t access a device if it’s off the grid.