The headline is wrong. It is not that people are watching you. It is just that everything is being recorded. The Internet breadth is approaching infinity. It is impossible for any organization to monitor everything on the internet no matter who they are, including the NSA. The only way anyone would 'watch' you is if you triggered a specific reason for them to spend resources on you. Child porn, terrorism, threats, international communications, etc. How many of the school shooters posted what they were going to do and nobody cared?
However, they do have the ability to review your record and see what you have been doing from the internet provider. All incognito does is it hides what you have done from other users of the computer you are using. It is very far from being any kind of secure communication. Everything is recorded by the provider anyway, whether you are using incognito or not.
Incognito is primarily used by people who are looking a porn and do not want the sites they visit to be recorded on their personal computer. And even that is not completely effective.