I don't thin the issue is Uber recruiting drivers. The issue is DOSing their competitor to do so.
I guess the question is whether sending requests and cancellations to 100 different drivers over 3 days (about 33 different drivers per day, maybe 4-5 per hour in a workday) really constitutes a denial of service. It seems exaggerated, but it is working as Gett is getting attention.
Definitely a bad idea though.