VideoPress »Restrict VideoPress playback by domain
VideoPress supports restricting embed playbacks to specific domains. Publishers interested in restricting playback must add allowed domains through the administrative interface of a WordPress.com blog with the VideoPress upgrade.
Setting Default Playback Restriction
Log into your WordPress.com dashboard and select “Settings → Media” menu on the sidebar. Enter a list of comma-separated domain names allowed to playback your video using the VideoPress Flash player. You may also choose a default embed option for new videos.
Setting Playback Restriction for Individual Videos
Restricted playback only applies to videos with embedding disabled. Individual videos you would like to restrict must have the embed preference unchecked in order for any restrictions to apply.