> This seems unjust given A1, A2, B1 & B2 were all just trying to collaborate in the best interests of their companies

Not really. This is the norms for industrial espionage, especially as Tokyo Electron is also working on the Rapidus 2nm fab project in Japan.

Furthermore, for these kinds of relationships there tend to be significant internal firewalls which were clearly overriden within TSMC.

And speaking from personal experience back in my individual contributor days in the security space, this attack path was a fairly common one for data and IP exfiltration.

> There is no allegation that the information supplied to B by A employees left B, or was used for anything except to help with the collaboration between B & A

From TFA - "The information, including trade secrets related to etching equipment used in 2-nanometer production, was photographed and reproduced to allow Tokyo Electron to evaluate and improve its equipment performance".

This was done without permission and done so by a vendor actively working on building a direct competitor to TSMC.