So lets do some math.
At least 250,000 people have used DNS modding in the past week.

If they were to be console banned xbox live would lose $55 x 250,000($13,750,000)every year in just xbox live subs. R* would then lose $2,500,000-$3,500,000 in potential sales from every DLC. R* and MS hate glitching and modding but when its on such a large scale what can you do?

Here's an example. A large number of the borderlands community hacks and mods. I have modded in both borderlands 1 and borderlands 2 throughout the entire history of both games and have never had even a warning. Yes, GTA is a larger game but what can R* really do? sort through millions upon millions of transactions in the game? They don't have time to even program something to do that. They are focused on DLC and simply fixing this huge security flaw in the game.

This wave of hacking and modding in GTA V is, in as respecful of a way I can say it, R*'s fault. They can't ban all these people because they would lose a large part of their community and would most likely lose future game/DLC purchases. R* cares about their games but, don't forget, they're a business and business loves money. In 1977 ford knew of a flaw in their pintos that would cause a huge fire if rear-ended and they figured it would be cheaper to just pay the lawsuits for the dead/injured people.

All I can see happening from this is R* fixing their game and maybe some money rollbacks. Anything else would be a kick to the balls of the accounting dept.