Block Image loading in any Android App

Q: How can I make sure that none of the android apps (installed) should be able to load any image(s) from Web?

Brief: Say I'm using 'Reddit News' and 'Reddit for Fun'. Although the latter allows no image loading for Reddit Entries, it doesn't control the images in links it open. The cost of having 3G connectivity is high in my country, or rather I cannot afford much of it, so image blocking is a must for me.

Note: 1) Device Rooted, so no issues for installing any app.

2) 'Adaway' installed but couldn't blacklist using regex(naive) expression.

3) Firefox and Chrome for Android has addons and extensions, so no worries at all about them.

Any idea(s) how to achieve this goal?