It's not the neutrinos themselves that are dangerous, it is the showers that are produced when the neutrinos interact with 'shielding' material between the source and the victim.

It's related to the problem in space colonization that the optimal amount of shielding is maybe 2 meters of lunar soil. Less than that and moderate energy particles are harmful. High energy particles mostly blast right through you but if one is stopped by a nucleus in the shielding, that nucleus will be blasted apart and particles from that could blow up more nuclei so a large amount of dangerous and penetrating (muons, pions) radiation is produced. It seems that some very high energy particles (neutrinos?) can pass through the earth and cause a shower, so it's not reasonable you can stop all of them. The earth's atmosphere is spread out over a long distance that gives particles a chance to decay so a shield that is better than the 2 meter shield would be difficult to construct so space colonists are going to accept a minimum level of radiation than we have on Earth.