E. Coli ends up in vegetables due to contamination from human or animal waste. E. Coli doesn't just magically appear on vegetables in a vacuum.
What pisses me off is that the media makes so much about e.coli outbreaks in spinach and green onions like it some huge health risk (and they rarely talk about where the contamination came from), but meat is routinely infected with pathogens, and people are merely instructed to cook it more.
Also, overall, there are only around 70,000 cases of e. coli a year (most of which are associated with meat consumption, BTW). Why isn't the media freaking out about the 1.4 MILLION cases of Salmonella reported every year? How about the 2 MILLION cases of foodborne Campylobacter reported every year? The number one source by far for both those infections is eating poultry and eggs or by drinking water that has been infected with poultry waste.
So everyone is freaking out because of 131 cases of people getting sick from eating commercially grown spinach that was contaminated by animal waste, but no one wants to talk about how the poultry industry is directly responsible for millions of people getting sick every year.
Don't get me wrong, I sympathize with people who were injured or who lost loved ones in the outbreak. But the outbreak was caused by contamination by animal waste, and e. coli has become such a serious health threat because of modern animal farming methods.