A hacker can use many ways of finding info about you. Just typing your public IP address (the address of your computer so web servers etc... know where to send data back) into an IP tracker can give quite a good accurate reading of where you are sometimes within a 1Km radius. Also key-loggers can be installed which intercept each key you press, also mouse clicks, programs open, even the particular website your on, which field (Text box) your typing in, can even take screen shots.
A hacker/spammer having your e-mail can definitely make you more at risk since an email selling market actually exists and the more that have your email the more emails you'll receive and the more likely you'll open a malicious email which then may download viruses, malware and even spyware.
Potentially Google is watching you, since most websites will leave cookies (A small file containing data like if your login session is still active, or your language) on your P.C and since the website name is also in the file, Google can sniff them out and target adverts at you from what you search.
Ways to avoid being hacked.......
Make sure you have an anti-virus, for windows I recommend MSE found here ------> http://windows.microsoft.com/en-us/windows/security-essentials-download
Get Malware Bytes Anti-malware and fully scan your computer remove all threats, 30 day trial found here -----> http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html?part=dl-10804572&subj=dl&tag=button
Download Ccleaner to remove cookies and temporary data here, run daily ------> http://www.piriform.com/ccleaner/download
You can also anonymously browse the web by using the Tor browser from the Tor project (Dont go on sites like Facebook because you most likely wont be able to get in to your account) but is okay for normal web browsing, you'll have to search using something like yahoo because Google donlike not being able to store cookie on your computer so they wont let you search using Tor, one last thing, Tor is basiclly a proxy however flashplayer is removed for safety although you can still enable it if you want to watch youtube videos..... the link ------> http://dw.com.com/redir?edId=3&siteId=4&oId=3000-2356_4-75660251&ontId=2356_4&spi=1b25c9444cd50a8b538001920ea7af3a&lop=link&tag=tdw_dltext
Also if you don't wish to use Tor there are other alternatives, download firefox ( http://www.mozilla.org/en-US/firefox/new/ ) and get these addons:
-HTTPS Everywhere - https://addons.mozilla.org/en-us/firefox/addon/https-finder/?src=search
-Tor badge - https://addons.mozilla.org/en-us/firefox/addon/tor-flashproxy-badge/?src=ss
-Do Not Track Me - https://addons.mozilla.org/en-US/firefox/addon/donottrackplus/
-AdBlock Plus - https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/
Hope I helped, please check out my tech info and help page on FB :) -------> https://www.facebook.com/UskisTechnology