Before you go online, you need to make sure that no one can hack into your laptop and start downloading with your mobile broadband connection...
But what exactly are the potential risks when using a USB dongle, and what security measures should you take?
The biggest risk
Because a mobile broadband connection is essentially a mobile phone contract, the biggest risk is that you'll lose your modem, or it will get stolen, because anyone could simply plug it into their own computer and download as much as they want - all of which would end up on your bill at the end of the month.
If you do lose your modem, or if it is stolen, you need to contact your provider and tell them as soon as possible to make sure the account is cancelled or suspended - just as you would with your mobile phone or lost/stolen credit card.
Local IP connection
Unlike a normal fixed-line broadband connection, mobile broadband users aren't assigned an internet IP address. Instead, you'll have a local IP address like you would in an office.
Although you won't notice any difference when you're browsing the internet, this actually makes your connection more secure. Just like in an office, your connection sits behind the provider's firewall, with a local IP address - making it far harder for criminals to hack.
However, it does mean that you won't be able to connect to your mobile broadband connection remotely from another computer.
Because mobile broadband uses the provider's mobile network where everything is already encrypted, it's like having a WEP or WPA key built into your connection.
It's not like wireless
Although it feels like you're using a wireless broadband connection, no one else could scan for your signal as they would be able to do with Wi-Fi. So if you're using your modem on a train or in a coffee shop you don't need to worry about other people in the area "hacking" in as freeloaders.
Mobile broadband routers
However, if you are using a mobile broadband wireless router or a mobile Wi-Fi dongle, you'll have to take the usual Wi-Fi precautions - such as setting a secure WEP or WPA key - so that unauthorised users can't simply scan for your signal and connect to your router.