I noticed, that Google is gathering quite some information about what kind of websites I’m visiting. I already noticed this, because recently I was surfing the web on my tablet researching some products and then a while later google would only show me this kind of products on ads. I was at first quite suprised, that Google as well as other sites only had ads for certain products, especially this kind of products I was recently interessted in. I then figured, that this is because of some ad-cookies that where stored on my tablet.
Well, looking at Googles new policies I noticed, that I could deactivate Googles gathering of products and using this information to personalize ads. This can be done via Googles-Settings page.
I also noted, that Network Advertising Initiative (NAI) is offering an opt-out mechanism for various ad-plattforms. So I did opt-out on all my devices from Google as well as NAI.
Besides opt-out I still use plugins such as AdBlock for Google or AdBlock Plus for Firefox. But at least for my tablet and my phone I don’t have such plugins, and I thing opt-out is a valid alternative.