Jerry, Eventually anyone doing this will have an injury of some kind - if you are really lucky it will only damage the workpiece, but more than likely you would get hit by a flying chunk(s) of wood. Another quite likely option is the do-it-yourself finger amputation! In the past when I've seen my helpers do this, I let them know in a very emphatic manner that is NEVER TO BE DONE!
When rip cut is made a long a fence, the longer workpieces have less tendency to skew slightly off-track than does a crosscut. With the crosscut, a teenie-weenie skew spells BIG PROBLEMS. Where you introduce the problem is at the friction against the fence.
(Cherryville) Chuck mentioned the stop-block nearest the infeed end of your fence. This is a method that we use * alot. Simply clamp a short stop-block to the infeed end of your fence - the protrusion SHOULD NOT be aligned with your blade tangent point - it should be closer to you. Use that stop-block as a reference point for multiple copies and if the workpiece is properly held-down - your workpiece is never exposed to fence friction simultaneously with being cut (friction ends prior to cut beginning). Many woodworkers literally wax their tablesaw tops and fences to minimize said friction.
* for crosscuts we most often go to the sliding compound miter saw. IN MY SHOP this is the better choice for boards up to about 16" wide.
Take care and be safe,
Otis Guillebeau from Auburn, Georgia
OPG3 Tweak everything!