People who use bankruptcy to run up other bills...?

...and then simple blow them off, because, hey it's bankruptcy right? I have a sister who went into default for a $100,000 plus home, lived there one year, couldn't make the $1,300 a month payments, moved to a farm where they coerced the old man owner that they could sell the place and make a balloon payment inside a year or two. Now the bank has the house, and she's filing bankruptcy, but they are putting several phones in their names, running up the bills, not paying any bills, yet still buying cars and four-wheelers, because they think they can keep aculating the debt. Is this moral? Of course not! Is this legal? That is my question!