Online Privacy - Google & Double Click

Recently google is trying to acquire the internet banner ad maket leader Double click for about $3.1 billion dollars. But the senators feel is that , how would this merger would affect the data privacy of users who have clikced through the ads. How would google treat this data that it is going to acquire from doubleclick.

For an hypothetical example google can use that data from double click and the corresponding IP, the banner ad context that you clicked on and correlate this information with the region and search queries to give you more personalized search results.