They will be reporting the details of their findings "once they are compiled and have been checked".
"We kept our measurement gear on, but we had to turn off the audio bleeps on the Geiger counter, its constant sound was driving us nuts. The alarms of the devices can't be turned off, and in particularly high radiation areas they'd all go off. There was one place we hit such a high reading that we didn't even stop there. It was windy and dry, and the dust and snow can carry radioactive particles. So if you step out of the car and get dust or snow on you, you might bring radioactive particles into the car and you don't want that. We moved on quickly.
We met the police at a blockade about 35 km out from the Fukushima nuclear plant, and they let us do measurements. Cars were still going in and out that didn't appear to be relief workers or firemen -- it may be people are getting permission to go in and get their belongings, but I'm speculating. It was not busy, but it wasn't deserted: there were still people going in and out."
Edit: Greenpeace has yet to release any official readings of their own, but one point we can already glean here is that safety levels set on their geiger counters were constantly buzzing from beyond the 35 kilometer 'safe zone'. Exact distances or prefectures were not indicated.
Certain areas were reading higher than others. Fukushima behaves like a point source to some degree - each reactor is giving off its own steady reading, but the surrounding areas have been affected by an aerosol distribution of fission products with wind-driven dispersal.
I hope Greenpeace has the kind of equipment that can detect signature isotopes, so we know exactly what's on the ground.