It depends on what you're talking about. VCC #'s generated by your CC company and tied to your main CC doesn't help much. They secure your actual CC #, but charges still link and appear as normal on your CC.Question : Does the new "virtual CC" option help the situation?
Prepaid VCC's act a bit different. Many are "anonymous" with no link to your actual CC. The down side though is that processing systems can use a variety of verifications so they may not be accepted by all. IE., some use only the number, expiration and security code. Others, the name on the card must be verifiable. Others still, name and a portion of the billing address must match.
They have improved a lot over time though and are increasingly more universally accepted.