IIRC a number of years ago a Learjet freshly hired by the Taiwanese Air Force was towing a target for a SAM test and the missile hit the Learjet instead of the target. Destroying the jet with no survivors.
Not a good idea.
*found a link*
http://en.wikipedia.org/wiki/Target_tug
"Target towing operations are not without risk. On September 17, 1994 a Golden Eagle Aviation Lear 35A was accidentally shot down by a ship of the Taiwanese Navy during a live-fire exercise.[5]"