People forget back in the 60's they were using back masking and other forms of subliminal manipulation in ads until the Government stepped in. But they never really stopped because they spent billions on researching this stuff, so they just moved to something else to control of influence people.

Essentially what they use yourself against yourself, which is why taking control of your emotions and using critical thinking is more important then ever. Know thy self!

How? like anything you practice, the more you practice the more proficient you become.