Swarmings?

Why, all of a sudden, are there so many swarmings in Halifax? That there have been seven recently makes me feel a little bit uneasy. I am not sure if I should take any comfort from the fact that they are in the North End or not. Anyway, I hope this situation is resolved shortly as it is somewhat disconcerting to think that 6 to 7 people might just jump me while walking down the street at night.