Can knowledge be haram?

Assalamu alaykum. I read a fatwa on your website under number #10762; here is the link: https://qa.muftisays.com/?10762 I did not understand one point. According to this fatwa, if someone started a business using stolen money, then later returned that money and all the income earned from the business, but the business continues to generate income because he replaced the capital with his own savings — does this mean that the person is obliged to give away all subsequent income from this business for as long as the business exists? My second question: if someone stole (or bought using stolen money) a laptop and learned programming with it, would the income earned later from that knowledge and those skills be haram? If so, does this mean it is impossible to purify this, and that for the rest of his life those skills and knowledge in his mind would remain haram and cannot be used? Please answer according to the strictest opinion among all madhhabs. As I understand it, the fatwa numbered 10762 is based on the Hanbali madhhab.