What is industrial action?

What constitutes industrial action and can thus be protected under the protected industrial action provisions of the Fair Work Act? That was the question before the Fair Work Commission in AMACSU v Lend Lease (2014) FWC 5676 delivered on 20 August 2014. Commisioner Bissett determined that each of the following activities can constitute legitimate industrial action.
The union proposed and the employer opposed a plan to
Attach union and industrial campaign-related material to outgoing mail or email, and add it to Lend Lease materials and displays;
Wear and distribute material such as t-shirts, badges, written communications and stickers in support of the proposed agreement;
Not respond to non-emergency emails or voice mail messages until after 1pm each day, with customers before then to receive an automatic message that: “I am currently undertaking industrial action because I believe staff should be treated with respect and decency at work. Because of this I will not be responding to emails [or phone calls] until after 1pm. If you have any concerns or comments please contact [or call] Lend Lease Contract Manager Malcolm Anderson”; and
Write messages on Lend Lease …. company cars “representing the concerns of Lend Lease staff” about the bargaining process.
The Commission concluded that all of the above constituted industrial action and thus could in the appropriate circumstances be protected industrial action.