My answer to your question is &quot;No, it doesn&#x27;t open up the personal cell phone conversations to monitoring&quot;. Because a personal cell phone is a personal device and there is an expectation of privacy once you start using the word &quot;personal&quot;, regardless of who owns the device.<p>I would actually add a bit more as the judges were trying to differentiate between work accounts and personal accounts:<p>&quot;<i>He argued that his right to a private life had been breached when his employer had read a log of messages on a Yahoo Messenger account he had set up for work, as well as that from a second personal one.</i>&quot;<p>&quot;<i>Despite claims about the second, personal account, </i><i>the judges only discussed the work account in their ruling</i><i>.</i>&quot;<p>&quot;<i>The device used to send the messages was owned by the employer, and the judges did not elaborate on whether it would have made any difference if he had used a personal device.</i>&quot;<p>The missing piece of this article is what does the company policy say? In addition, it&#x27;s clear the judges are saying that if you are using the work (corporate) network, you should not have any expectation of privacy, regardless of who owns the device.<p>What is unclear thing is who defined&#x2F;authorized the personal account he created while using the work network? If the company authorized it, then they cannot log it and there is indeed an expectation to privacy. If they didn&#x27;t, and he is simply personal making accounts using the corporate network, then he would not have an expectation of privacy in my opinion.<p>I&#x27;m also surprised only 1 judge said &quot;<i>One of the eight judges disagreed with the decision, saying that a blanket ban on personal internet use was unacceptable.</i>&quot;<p>There should always be some room for personal use e.g. calling your doctor, kids at school, etc. A blanket ban is not practical at all and can never be fully enforced.