Hacking is when someone breaks into a computer and tampers with your things, like documents, firewalls, websites, ect. Also, it reprograms a computers so all of your things are gone or redesigned. It affects a web designer because if a web designer designs a website for someone or his/herself and a hacker hacks into it, they could lose all of their work and would have to start over. This could also affect the user because if someone goes to a website that someone designed for them, and it's not what they wanted they could sue the web designer if they paid him/her to design it. This is really bad because the web designer could have done everything right and someone could have hacked into it without the person knowing.
I think it's a very bad thing to do. I don't think anyone should be able to insert themselves into other peoples' business or websites. I don't really know why someone would want to re-program a computer and tamper with peoples' things. It's such a hassle to get everything back to normal and it's a waste of time.