I can understand why she wants the coupons from neighbors' newspapers, etc. Many of you mention that all she needs to do is use the internet. However, I'm sure that she already is using the internet to print out coupons, along with clipping them out of newspapers, peel stickies off of the items themselves, pull coupons from pads on the store shelves, etc. But the trick is to get coupons from many different sources, and then match up store specials with the coupons that you have. Even though there are coupons on-line, they may not be worth as much as one in the newspaper, or it may limit to a certain size which doesn't match what the store is running it's special on. Also, when it comes to extreme couponing, you want to be able to buy as many of the item as possible when the price is extremely low to stockpile it for later when the price is high. So getting the same ad insert from multiple newspapers allows you to have multiple copies of the same coupon with which to purchase the same item multiple times for the low price.
Now what the lady did was wrong... Instead of just taking the coupons without permission, she should have just talked with the newspaper owners and see whether they'd be willing to give her the ad inserts. Some extreme couponers with make a trade with their neighbors; they get the neighbors' ads and in return when a certain item the neighbor wants finally gets to a very low price, the extreme couponer will buy up that product and give it to the neighbor in exchange. Also many businesses (eg coffee shops, waiting rooms, etc.) may get a subscrition to a newspaper for their customers to read, but may not have a use for the ad inserts, and so would be willing to give to the extreme couponer for free if they asked the business manager / owner.