Two issues in this story: Because registrars allow you to return a domain without costs within 5 days, domain kiting or tasting allows unscrupulous companies to register a domain, see how much traffic it generates and throw it back for free or re-register it every 5 days, allowing them to get free domains. Apparently the scope of this problem is huge.

The second issue is that so called reputable companies (such as Network Solutions) are posting your searches for domain names, so that above unscrupulous companies can register them before you can.