In Michigan last week, a non-union business owner was shot outside his home, and the word “SCAB” etched into the side of his car. In New Jersey, a striking union worker had his young daughter stand in front of an oncoming Verizon truck. In Virginia, phone and cable lines were slashed, cutting off service to Verizon customers in dozens of neighborhoods.

According to Verizon, there have been 202 reports of sabotage and vandalism since workers began striking 12 days ago. Unions have always used strong-arm tactics, but recent protests seem even more violent and fanatical than usual.

And it could be because unions are weakening. In the case of Verizon, the striking members are land-line workers engaged in fight over benefit payments. But the employees don’t have a strong negotiating position, since Verizon isn’t making money off land-line customers. The Atlantic’s Megan McArdle writes that this could be the reason the fight is spiraling out of control:

This situation is pretty much unprecedented as far as I can remember.  Usually union workers are found in the core business of a company–when the company’s fortunes decline, so do the fortunes of the union.  But in this case, the union workers are becoming less valuable every year, even as Verizon is worth more. No wonder this strike seems to be getting so ugly.

Union membership has been decreasing steadily for decades, but it tends to wane even more during economic downturns. Couple that with the recent Wisconsin election failure, and unions are likely legitimately concerned about their future and reputation. That’s the kind of desperation that leads to erratic, even dangerous, behavior.