Is it permissible to sell computer programs although I am afraid that they will use them for sinful purposes and that I may incur a burden of sin as a result of that, or am I not responsible for what the purchaser does after he has bought it from me?

I am an engineer working for a company. One of the perks that I get in return for my work is a sum of money to compensate me for what I have spent on updating my engineering skills, such as conferences and books. If I do not use the money during one year, the company keeps the money. The company also allows me, as a one-off, to buy a computer without stipulating any maximum limit on the price of this computer. Some of my colleagues who have the same perks bought a computer and gave the invoice to the company to show that they bought this computer, then they returned the computer to the store and took the money and kept it. Is it permissible for me to do the same thing?.

What is al-‘Aqeedah al-Tahhaawiyyah? What is it about?

What are the most important rights that are respected in Islam?

I hope that you can explain the virtue of the Sahaabah and what distinguishes them from others?