caran1 - 2:25 am on Nov 5, 2006 (gmt 0)

Is it possible for a competitor to get websites removed? I have many websites, static HTML, unique content, more than 1 year old. But for only 2 websites when I login into Google Webmaster Tools, I get the message
"No pages from your site are currently included in Google's index. Indexing can take time. You may find it helpful to review our information for webmasters and webmaster guidelines."
Earlier I was getting a lot of traffic from Google , now it has just disappeared from the index. I have not received any notification regarding penalty. I had also submitted a sitemap which was accepted without any error.
How do I find what the problem is?