Then leave the company in protest or convince it not to buy them. DDoSing the company's network is somehow not unethical, I guess?
Collective action (strikes, "work slowly protests" etc.) as a protest against company policy has a long precedent of a) being protected by law and b) being much more effective than a single employee quitting, while simultaneously reducing the downside for employees (in L_\infty norm).
Edit: the old Keynes quote comes to mind: "if you owe the bank $100 you have a problem, but if you owe the bank $100 million the bank has a problem" -- if 1 of the company's devs commits a "fireable offense", he/she has a problem, but if 100 of them do, the company has a problem.