Remember that Immigration Inspectors can look at your social media
This story illustrates that when you make an entry to the US you should assume that Customs and Border Protection Agents can not only look in your bags, but the can check out your face book or my space accounts too. This is also the case when you make an application for a visa at a US Consulate or Embassy.
http://bangordailynews.com/2011/07/07/news/downeast/canadian-folk-singers-charged-with-illegal-entry-across-calais-border/