Someone is stalking me on here and I am alarmed, how were they able to track me down ?

[Robert K]

Try to put your self in their shoes:

check what your privacy status is and what information is available about you,
in your answers you might have revealed information or information from which somebody can make conclusions. DO you have any links to facebook ? Is your profile on extreme private mode ?

Second is: when they send you the emails: what exactly did they say ? What are the exact details they gave you ? You can send an email to everybody claiming you have information ....