This forum is specifically for Firefox issues. Wider security issues and questions should be discussed elsewhere. I can not really suggest where as it is such a broad topic. Related Firefox advice includes * http://www.mozilla.org/en-US/firefox/phishing-protection/ * [[Create secure passwords to keep your identity safe]] *[[How do I tell if my connection to a website is secure?]] * [[Security and passwords settings]] -------------- Rather than ignore your question as out of scope a brief reply is : Short answer is no you need not worry. <br /> The laptop needs to disclose such information to be used on a network. A longer answer is that you should be aware that what you do is almost never totally private. By the way In many cases the IP Address will be dynamic and may occasionally change depending on your setup and how your provider works. If you wish to be only slightly paranoid then using WiFi is itself inherently riskier than using a cable connection. Employers & Internet providers etc are likely to be able to track your use of their system. There are many things to consider with network and PC security you may find this a useful starting point *Best Practices For Keeping Your Home Network Secure <br /> http://www.nsa.gov/ia/_files/factsheets/Best_Practices_Datasheets.pdf * this is an older document but still with simple technical explanations <br /> http://www.cert.org/tech_tips/home_networks.html For any detailed advice may I ask that you try elsewhere.