This article is from the Digital Broadcast Satellites FAQ, by Brian Trosko firstname.lastname@example.org with numerous contributions by others.
Macrovision is a copy-protection signal. It can be
embedded in the signal alongside with DirecTV and USSB programming.
It results in any recordings being unwatchable due to fluctuations
in color and synchronization. Neither provider has turned
Macrovision on; DirecTV reserves the right to do so, and USSB
claims they have no plans to ever do so.
If the Macrovision logo present on the back panel of the more recent E*
receivers is any clue, E* also have the capabilities to activate the
Macrovision copy protection. So far as is known, Echostar has no official
position on future use of Macrovision.