I use the internet. You use the internet. Just about all of us use the internet.
Including bad guys...
But that doesn't mean that only bad guys use the internet. Just as it doesn't mean that the only people who have knives in their kitchen drawer, or hire rental cars, are murderers.
I use the internet to communicate and help plan my day. You use the internet to communicate and help plan your day too. Just about all of us use the internet to communicate and help plan our day.
So, yes, of course terrorists use the likes of Google, Facebook, and WhatsApp because they're useful tools.
Would weakening or banning encryption (as some politicians would like) stop terrorism?
Even if politicians could convince technology firms to give them a backdoor into their systems, criminals would simply stay well clear and use alternative systems that guaranteed they didn't have law enforcement breathing down their necks.
Terrorists and paedophiles might even download the source code of a secure end-to-end encryption messaging app, and compile it on their own PC.
Where would a backdoor in end-to-end encryption apps leave the rest of us? With mainstream messaging apps that fail to secure our privacy, that could potentially be spied upon by law enforcement, organised criminal gangs and rogue nations.
Do you want to live in a world where it's impossible to have private and confidential conversations? I don't.
Furthermore, I believe in my right to protect myself from the incompetence of others. Every day we read headlines of huge data breaches - either through hacking attacks or human error (or often a mixture of both).
Properly implemented end-to-end encryption (with no backdoors) means that if technology companies cannot read our messages, then hackers can't get at them either.
You use encryption many times every day. You use it when you make an online purchase. When you log into your favourite website. You're using it right now to read this article.
Encryption isn't a bad thing. It's a good thing. It protects your privacy and secures your information. It stops hackers looting your bank accounts. It saves lives from oppressive regimes. It defends us from intelligence agencies that are prepared to break the law to collect vast amounts of data about us.
There is a danger that politicians will take ghastly incidents of terror as a platform to push forward their agenda of weakening encryption. It makes for an easy headline. It makes them sound tough in the fight against terror - at least to people who don't know much about technology. But it won't make a blind jot of difference to bad guys.
The people it will most hurt are the regular members of the law-abiding public.