I need help,this troll,keeps hacking into my google/usenet account,how is he doing this??

I need help,this troll,keeps hacking into my google/usenet account,how is he doing this??
I keep deleting my google/usenet user names & passwords.
I create a new user name on google/usenet. I even create new passwords.
Yet this troll,still manages to hack into my google/usenet account & post replies/threads using my google/usenet user name+password.
I checked is profile info on google/usenet. he's from the UTC time zone & he uses a iphone/touch.
everytime I delete my google/usenet account+password,then create another google/usenet+password. then I create a thread on google/usenet,one hour later the troll hacks my account & post's replies under my user name.
how is he doing this? does he have some kind of software program that allows him to run passwords super quick & find mine.
does he have some sort of virus or tracking cookies on my computer? I ran 2 anti virus programs which were eset on-line & microsoft safety scanner on-line. I ran both anti-virus program doing a full scan looking for tracking cookies & so forth,they reveal zero viruses & zero tracking cookies. plus I have a windows 7 fire wall.
So how is this troll havking into my google/usenet accounts one hour after I create them & post a thread on google/usenet?
any answers would be greatly appreciated.
I keep deleting my google/usenet user names & passwords.
I create a new user name on google/usenet. I even create new passwords.
Yet this troll,still manages to hack into my google/usenet account & post replies/threads using my google/usenet user name+password.
I checked is profile info on google/usenet. he's from the UTC time zone & he uses a iphone/touch.
everytime I delete my google/usenet account+password,then create another google/usenet+password. then I create a thread on google/usenet,one hour later the troll hacks my account & post's replies under my user name.
how is he doing this? does he have some kind of software program that allows him to run passwords super quick & find mine.
does he have some sort of virus or tracking cookies on my computer? I ran 2 anti virus programs which were eset on-line & microsoft safety scanner on-line. I ran both anti-virus program doing a full scan looking for tracking cookies & so forth,they reveal zero viruses & zero tracking cookies. plus I have a windows 7 fire wall.
So how is this troll havking into my google/usenet accounts one hour after I create them & post a thread on google/usenet?
any answers would be greatly appreciated.