Hackers
My past websites have been hacked a few times before, let alone my online accounts. In the internet, nothing is safe. Everything on the internet can be seen by anybody who has access to it.
To secure you online, you should start with your own computer. If somebody else is sneakily using your computer, you can use a device like a keylogger. They capture passwords, chats and screenshots. And it’s undetectable and also logs website history. It’s like a USB-ish device, but can do at lot more than a usual USB.
You can get them at websites like Brick House Security. It’s available on most websites for home security :)