Diplomacy hit for digging artifacts?

I cannot seem to find the exact numbers, maybe somebody has a link or some direct values for me?

If i dig a single artifact out of a dig site within another civs borders i get asked to stop.
If i say "i dig wherever i want" i get a flat diplomacy hit (of 10, i guess)?
Do i also get a hit for each subsequently digged artifact?

In our game we have a lot of dig sites within the borders of our neighbour (which we are currently friendly+DoF with). We don't want to risk becoming their enemies, but we really want their stuff

I don't believe there's any hit for stealing one artifact from an AI civ and try to steal one from several if I can do it in time.

When they tell me to stop, I stop as I presume there's a hit for telling them you'll dig where you want to, and a big diplo hit for lieing about stopping.

Twice I've tried to get away with stealing two artifacts from the same AI on the same turn, but the game realizes it and I got a diplo hit, although I think it is small.

.. neilkaz ..