My question may seem very amateurish or even incorrect, but do please take in account that I'm a complete noob in computer and network security. I'm just trying to find out some information here.
Most users do use quite weak passwords for their home systems, many of them actually do use the same password for root/mail/forum/social network accounts, and its a fact. So, bearing this in mind, is it easy to hack a computer of such a user? A hacker finds his IP address (just a random pick I guess) and then decides to crack it. Will it be easy or not? How much time will it take? And how difficult will it be to hack a strong passworded PC? Maybe a good hacker will not need a password at all, I don't know. As I mentioned above, I don't yet understand all the ins and outs of networking.