Why is googleads.g.doubleclick.net showing up in my adsense reports ?

I looked all over the internet to find a quick simple explanation for this. After reading a few google help documents and doing some research online, reading others experiences.

 I found that, the reason for this is that "googleads.g.doubleclick.net"  to keep track of Adwords sites and Adsense click revenue google uses a system called Auto tagging, basically what it does it appends some text to the end of your URLs for tracking revenue and what users do on your site to determine the cost. When you bookmark pages it throws this information off as you are coming in from a URL that might have been previously generated. This is why you might see it in your adsense account. If you are using google adwords make sure not to link directly to the generated URL as it will provide google with the wrong tracking data = cost.

for more information on this topic I recommend reading: https://support.google.com/analytics/answer/1011829?hl=en
:support page provide by google on this topic

DDoS attacks are caused by Short link URL providers.

This is Just a thought that I came across while researching ways to make money online and thinking about all the recent news and rumors about DDoS (distributed denial of service attack) attacks around the same time I also received an email from Intermedia.com reporting possible DDoS attacks against NetworkSolutions.com .

Let me explain, I have noticed a huge number of new link shorting companies that are willing to pay if you use their services to shorten your links.
They normally pay a small amount (ranging from $4-6.50) per 1,000 visits.

I noticed however that when you create the short link the new link they provide is under their domain this means that at any given time they can point all their traffic to a specific IP bringing down any server that can't handle the traffic.

Let me know what are your thoughts on the possibility of this being true.