Huge traffic from Piwik Tracking URL!

Hi all, I have a rather weird problem? Or maybe even Gain! But I couldn’t find any answers anywhere, so I thought I’ll give this a go.
So here’s the issue: I created a tracking URL for my bing/yahoo PPC ads so that I can track which ads perform the best. I used the URL builder to create the tracking code that goes on the end of my domain name.

Ok, so the ads were running, I was able to determine which ads was bringing in the traffic through the Piwik web analytics program. Anyhow, the Piwik Tracking URL has been indexed by yahoo/Bing search engines. I.e. name

That whole URL has been indexed and the first day I used the tracking, I also received 500 hits from facebook in just 5 hours and it was again, the tracking URL that had seemed to be indexed or linked to by facebook. Worried, I contacted MS, just to make sure I wasn’t getting charged for this traffic onslaught. The thing is, the tracking URL was intended to track my ads, but instead it’s been indexed!

So if I do a search under my keyword terms, the whole Piwik tracking URL shows in the results.
So what I discovered is: if you create the tracking URL to use with Microsoft Adcenter, this somehow causes that URL to get indexed really quick, with FB and Pinterest also linking and bringing heaps of traffic to my website. The tracking url had brought the most traffic EVER, compared to just the URL on its own. The ads somehow trigger the events!
Does anybody know what is happening? Is this a discovery or a Pandora’s box that has just been opened? Confused!
Cheers BlueEnergy

That’s quite surprising indeed… Sorry I have no idea what happened as no XP with ad center, but if you find out more please let us know