Why did my Blackberry bill skyrocket after downloading free apps?

[DelightoftheNight]

I downloaded many free apps. I have a data plan (not unlimited). Basically, the story is, I have a regular data plan. I downloaded many free apps and they ended up skyrocketing my bill. I was wondering why.

 

[zbalat]

Downloading apps free or paid uses data

Using apps that are free or paid uses data