There is a local tradition in Switzerland, and some parts of eastern France and southern Germany where roads are given to cyclists for a "slow up". Cars are banned on the route. Tens of thousands of people are on the road, there are local festivities, music, food stands and drinks and it's a really good time for everybody.
So they didn't storm the vineyards? They just rode their bikes along the roads next to them?
Why did the title say they stormed the vineyard?
I guess they wanted to bait people into clicking