How much does a couple of hours of people standing in the parking lot waving signs really cost them? It's not like Google is a manufacturer where the assembly line comes to a stop if nobody is on the line; everything should be automated so that a handful of people can keep the servers humming along in the data centers. Maybe a few status meetings of dubious worth don't happen, or a little less email gets shuffled around.

Most people aren't actually doing anything that really affects the bottom line in a typical software company. Maybe if a few people performed acts of sabotage as a statement, that would make a dent, but that would effectively be suicidal.