Online Advertisements

I would love to know who thought it would be a good idea to create online video ads that start playing with no warning. These ads seriously give me a heart attack every time I'm on a website and they start automatically. The worst is when I have multiple windows open and I have to search through all of them to find the source of the noise. Honestly, when I encounter the ads I never end up having positive feelings towards the advertiser; I am usually annoyed, frustrated, and angry. I think advertisers need to find a balance between engaging online advertisements, and ones that are just plain intrusive.