While this is possible, it is unlikely. Unless if you have a static IP address, you are too elusive on the Web. Every time you log on with your ISP, you are assigned with a new IP address that was randomly selected from a large pool of addresses. The probability of getting the same IP address next time is rather small and a possible hacker who was busy trying to get into your PC, has lost you. He will have a hard time to find you again.
Condensed to a small scale, you get two kinds of hackers on the net. One is the ankle biter who has nothing better to do. He is the villain who will delete your data files just for the hell of it. If he is smart enough, he’ll install a script on your hard drive to delete your system files next time you start your machine. He found you by accident, he’ll do his thing and scoot off without even wondering who you are. A pain in the a**, but nothing that cannot be overcome by keeping a proper backup.
The other one is more dangerous. I call him the cyber spy. He wants information and normally he wants large volumes of it. Unless if you have very important data on your machine or something specific that he (or his client) may be interested in, he will not find your machine attractive.
What is the danger then? Because this is the scoundrel who will hack the Gmail, Yahoo, or Facebook servers. Those servers have large volumes of personal information (about you too) that can be sold to mailing companies. Or scammers will use the information to scam you and your contacts with the information they gained by reading your emails. They will not advertise their presence on the server, as they want to come back for more info later. A tip here is never to leave any information on the mail server. Use a mail client like Outlook Express or Thunderbird to download your emails to your PC and keep all your contacts on your PC. Leave nothing personal on the mail servers.
And CS? Will they be hacked? I suppose it is possible that some have tried, we won’t know and they won’t tell us. However, CS keeps preciously little useful personal information about us and data collectors won’t find it lucrative to spend the time hacking it. If your personal profile was hacked, you will probably find the security breach closer to home. Keep your passwords safe and secret.
Most hackers gain access to your PC via a user account that does not have a password. Make sure that every user account on your PC is password protected. You cannot prevent hackers from gaining access to your PC. It is like protecting your house against burglars. If they want to get in, they will. You can only make it difficult for them. A hacker needs time to hack a PC. Don’t give him that time. Don’t stay online while you go to the supermarket.
As a consolation, your PC is a low priority target. It will only attract the ankle biters. There is nothing to gain by hacking it. It is the fat web servers, hosting large databases that are at risk. Thieves won’t break into houses where they don’t expect to steal something valuable. Even Robin Hood robbed the rich. There was nothing noble about that; the poor had nothing worth stealing.
Have a great weekend.