Which witch? Walpurgis night pranks fade in Germany

Merriam  Webster has this somewhat roundabout definition: the eve of May Day on which witches are held to ride to an appointed rendezvous.

That would be April 30 for  you and me but the dictionary definition has the great advantage that they won't have to change it if someone adds a day to the month of April, removes a day, or even throws April out of the calendar!

The Encyclopedia Britannica boldly states April 30 and gives details on the countries where the event is celebrated today.

We wanted to know how the tradition is expressed in our southern German hill country and investigated a bit. 

The findings were disappointing, there is not much going on at all. You may see a Halloween clone gaggle of witches in a newspaper photo with a caption on brooms and the Blocksberg mountain up north, but otherwise, nothing really, say the locals.

Then they will launch into crazy tales of yesteryear, stories of heavy drinking, of pranks and at times serious property damage on the night of the witches.

Young men used to roam the small towns and villages from around midnight on April 30 to early light and perform acts of mischief that were then blamed on witches.

Savor that sentence for a second, please.

Can you give us some examples of pranks?

The most benign and most common ones would involve moving objects around that people had not secured for the night, like flower pots, garden tools, construction materials, farm equipment. Any such item would be moved over to a neighbor, hidden in or under something - you get the idea.

A step up, you'd have items removed from supports with tools, for instance shutters or other bolted down objects, and taken as far away as the other end of town, making it time consuming and annoying for the owners to retrieve their stuff.

Then there were elaborate pranks involving a large effort that reached the status of a work of art, if you will. A favorite in this category involved a farm wagon/trailer and a communal baking house: a group of young men disassembled a wagon and reassembled it on top of the steep roof of a standard German communal baking house, some 15 feet up in the air.

A group of its own were pranks that could ostracize people, cause emotional distress or even hurt people. One such distasteful episode was told to us by an old man who chuckled as he explained it. 
They attached two cans of pig blood one of the group had saved when they had butchered a pig at home a few days prior. They had engineered a contraption that attached above window shutters and which would discharge the cans when the shutters were opened.
They stood back and pelted the shutters with gravel until the residents opened first the window, then the shutters.
The cans released their contents, the owner, startled by the liquid, turned around, and his wife screamed as the kids ran.

None of this happens today.

When did it stop and why?

Pranks began to diminish some 20 or 30 years ago. People complained to the police over destructive pranks, there were fewer houses that had stuff lie around, fewer farms. And there was much more to do for youngsters out in the country, they'd hop into their cars and go party in the city, many would move into the cities to go to college or simply to leave the rather constrained rural life.