Use of technology is changing the nature of French strikes. More and more people are using apps to share rides, bikes or scooters as a mass-transit strike drags on into a sixth day. Trains and subways are at a standstill. Commuters are frustrated but discovering ways to get around. Some are finding places to sleep near their workplaces via Facebook or online couch-surfing communities. Carpooling apps especially are seeing a spike in business. The development is undercutting unions’ power to paralyze the country.