UN: Hamas seized food and blankets from needy Gazans

Hamas is the rightfully elected govt. They are the democratically elected representatives of the Palestinian people.
Any govt would react this way if a foreign entity were trying to undermine the elected govt by supporting its rivals.
For instance, if Pakistan needed aid, and the UN purposely supplied aid only to a rival govt faction at the expense of the elected one, then Pakistan govt would react in the same way.

At least we know that HAMAS is know and credited with being far less corrupt and far more trustworthy then other factions. After all, that is why they were elected. So we can rest assured that seized or unseized, the aid will get to those who need it most.