What a load of baloney. 2,4-D does not metabolise in the body. The studies linking adverse health effects to 2,4-D are overwhelmingly outnumbered by those concluding it is safe. More than just that, those claiming adverse health issues have been incredibly flawed and most were based on agendas by competing pesticide companies back in the day - we have come a long way in our testing of 2,4-D since then. The agent orange link is superfluous as 2,4,5-T was the compound of concern in Agent Orange for dioxin contamination - not 2,4-D. Every single agency ever tasked with researching the health concerns of 2,4-D has come to the same conclusion - based on years of research, no evidence links 2,4-D to any adverse health issues.
The article you linked to goes on to state that it has been banned in certain countries. Yes, in some countries they went over the top in the banning of pesticides in the early 90s. Subsequent research has acquitted 2,4-D of any wrong-doing and even the European Commission has concluded that 2,4-D should no longer be deregistered for use anywhere in Europe. Of course you don't have to listen to the EU - many countries simply use different pesticides these days and therefore there is no need to re-register its use.
While prolonged exposure to many chemicals can be harmful, in the quantities in GM crops; the lack of metabolisation in the human system; the incredibly short half life; and the distinct lack of evidence pointing to it being harmful, imo there is no need to kick up a storm about this in our food.
The fact that the authors attempt to draw a link with Agent Orange and make quite a few false claims about the stuff, shows you that they have a very clear agenda. Often these supposed protection groups are merely protecting the interests of their companies, in much the same way as they claim that every single researcher on the planet who has researched 2,4-D is in on the conspiracy too. Don't believe all of their tripe.
And GM crops are not inherently harmful. Yes, we have to be careful how we manipulate them, but claiming "we don't know how they will affect us in 50 years' time" is a schit argument. And it is about all GM crop haters really have...