Not sure how ethical it is to buy foreclosed homes that are being foreclosed due to non-payment of taxes. Buying such homes could displace a family in need.
However, some of the homes that are being foreclosed on are uninhabited. Across the street from our little piece of undeveloped property in eastern WA is a scary fixer that went up for auction last month. A neighbor told me when it was going to be auctioned, so I joined the public auction website in order to watch the bidding process. I was surprised at how many people bid on that place. The opening bid started at $2,700.00 (the total amount of back taxes). It ended up with the price of $25,000.00. I was glad to find out that a young man who grew up in the town (semi-ghost town out in the middle of nowhere) and still lives there bought it. The house has big problems: the septic doesn't work, the well dried up years ago, and there's a gaping hole in the roof and mold in the area of the house where water got in. But still, a solidly built house, built about 1930. It will be a decent place when fixed up.
So if anyone is interested in buying county surplus tax auctioned homes or undeveloped land, you can view property in various states from the public surplus website. Cash is required for all purchases.
I wouldn't want to put a family out on the street either, but by the time it gets to that point, the home is usually vacant anyway, and very often you can't even find the people. It would be kind of strange for someone to be able to pay their mortgage (assuming they have one) but not be able to pay the taxes, and besides, the lenders either have to get the tax and insurance payments from the borrower to put in escrow, or the borrower has to provide proof of T&I having been paid. So if there's a mortgage, it's pretty much a fail-safe situation that T&I will get paid somehow. The usual scenario is that the borrower can't make their monthly mortgage payments --- at which time the entire amount becomes due and payable, you can't make partial payments (people try this, but the payments can't be applied without the collections department putting together some kind of plan, the goal being to bring them current in X number of months) --- they fall far enough behind that foreclosure becomes more and more of a reality, and they vacate the premises, leaving it up to the lender to maintain the property, pay T&I out of pocket, and so on. No lender wants to see a delinquent property get sold for taxes, and they certainly don't want to see the house burn down without insurance and be left with land and a teardown (unless it's someplace like San Francisco, where the land is what's dear). But if they own the home free and clear, yes, theoretically they could lose the home for non-payment of taxes.
As I told our director one time, people who make their payment (including T&I) every month without fail, are a "cash cow", they never cause a problem, and on average the servicer (the entity who processes payments) pockets about $30 per month in service fees without working up a sweat. (But you have to pay your people and your overhead out of that $30, which is why they are so niggardly about hiring more people, economies of scale, you know.) The one to three percent who don't, that's where all the headaches come from. Kind of like the shepherd leaving the 99 sheep to go look for the one that has wandered off.