Are there any negative affects of accepting the hackers' deals?
According to this wiki, there are 2 Blowfish events:
1) Industrial Spy Topic: If you accept you gain a "new game topic" and +1 Evil point. If you decline the offer, you get +1 Good and +1 Secrecy.
2) Industrial Sabotage: If you accept you gain +1 Evil. If you decline, you gain +1 Good.
Other than these listed, there seem to be no other consequences.