I have been staying away from canned beans (except in a dire emergency and I just NEED to have those canned chickpeas in my recipe tonight!). However, I do keep cans in the pantry just in case. The reason I stay away from canned beans (or many canned foods for that matter) as much as possible is this: I've read that they are lined with BPA (Bisphenol A). The same substance lining many food and drink cans. On the rare occasion that I do buy canned beans, they are usually Trader Joe's or Eden's brand since they don't line their cans with BPA. Here's a link to a site listing some companies that don't line cans with this toxin - http://bpafreecannedfood.wordpress.com/bpa-free-canned-food-brands/
According to the NY Times (http://well.blogs.nytimes.com/2011/11/22/bpa-lurks-in-canned-soups-and-drinks/), people who ate one serving of canned food daily over the course of five days, had significantly elevated levels — more than a tenfold increase — of BPA, According to the NIH, BPA in food and beverages accounts for the majority of daily human exposure to this toxic chemical which the Times writes, "has been linked in some studies to a higher risk of cancer, heart disease, diabetes and obesity, and health officials in the United States have come under increasing pressure to regulate it. Some researchers, though, counter that its reputation as a health threat to people is exaggerated." My take on it? "Why tempt fate?" I'd rather err on the side of caution. Hey, many years ago doctors recommended menthol cigarettes! We've come a long way since then.
So, do yourself and your family a big, healthy favor. Start buying dried chickpeas, lentils, black or red beans. Soak the ones that need to be soaked - so you have to plan your meal ahead a bit. You can always soak and then cook them and use them in a few days. You'll not only get more nutrients into your body, but you'll keep help toxins out.