Install referrer parameter values modified by Face

问题:

I used Google play install referrer in my android application and used the following parameters and generated URL as it was described:

utm_source,
utm_medium,
utm_content,
utm_campaign

I wrote my own custom receiver and all worked fine for me, while installing my application received broadcast successfully.

I posted the application URL on Facebook and when I received broadcast my parameter values were changed.

For example I sent:

utm_source=somesource,
utm_medium=facebook,
utm_content=samplecontent,
utm_campaign=xyzcontent

and while receiving every time i am receiving the same following values in parameters

utm_source=apps.facebook.com,
utm_content=myAppId,
utm_campaign=fb4a

Why Facebook is changing the parameter values :( ? Is there any way to keep values intact?