Well, it's part of Arabic culture as well, to us it may seem a bit strange to pointer lasers a pilots that are our friends and even throwing out new little flags from the helicopters.
In these video's you also see some fireworks that go pretty far up in the air with helicopters fly over very low - apparently also without any damage though that could be more luck that wisdom (imagine a jet turbine ingesting a pyro shell, jeez).
Then again, those lasers will not impress these people. In Cairo it's not common, but in more rural areas it's custom to fire automatic weapons in the air when celebrating weddings and such. Obviously those bullets come down and can (and do) harm people so this isn't done in major cities, but in small villages where everyone is essentially attending the celebrations it's still quite common.
