Loading preview images from a websites articles into thw cache for later use. What could go wrong?

*26 images (80x60) images in my cache folder, most of the corrupted.

"Ok... let's look at the size of this folder"

Size: 112MB

WTF How could this happen!

I'm litterally writing a from a URLConnection to a file.

*Checks data usage

Jup, that amount has been downloaded. Why!?

My dear monthly data ¿_¿