UK Man Held Over Cisco Source Code Theft  LONDON (Reuters) - Police said on Monday they have arrested  a 20-year-old British man on suspicion of stealing Cisco  Systems &lt;A HREF="http://www.reuters.co.uk/financeQuoteLookup.jhtml?ticker=CSCO.O qtype=sym infotype=info qcat=news"&gt;CSCO.O&lt;/A&gt; source code, the basic instructions for the  machines that direct Internet traffic across the globe.