Why you shouldn't host your site through the firm who builds it

I've written previously about the importance of maintaining control over your website and wanted to post this follow-up.  In addition to having your site's domain registration in your company's name and billing, you also want to have your hosting account in your company's name and billing.  The reason?  You are able to choose who works on your site without moving your site to a different server.  Have a falling out with your web guy?  Or he/she simply fell off the face of the earth?  No problem, you have control over the hosting account.  Change the password and find a new consultant to work with.  Give them your new password.