I would assume you're still allowed to post your to social media in Australia. Security clearance is not a role. I doubt people post they have access to all the infrastructure on their linkedin but you can infer it by the role.
Linkedin doesn't even matter since you can buy the data any way. Email Signatures are mined to get role and contact info for databrokers. Anytime you email outside of the org, the CRM software could be grabbing that info and feeding back to a databroker. Not to mention people using addons to their mail clients. Why I don't use one at my current company even though it is company policy to have one from our HR department. Thats just email. There's also the credit report data that has your role on credit applications and also when you donate money to politicians/PACs that makes you list your role for compliance reasons.
Yes, I don't know any company in Australia that doesn't allow you to post to social media. In fact in the company I work for it is actively encouraged.
My point being is that there are details you aren't allowed to put on your social media accounts, for the reasons we're debating.
Linkedin doesn't even matter since you can buy the data any way. Email Signatures are mined to get role and contact info for databrokers. Anytime you email outside of the org, the CRM software could be grabbing that info and feeding back to a databroker. Not to mention people using addons to their mail clients. Why I don't use one at my current company even though it is company policy to have one from our HR department. Thats just email. There's also the credit report data that has your role on credit applications and also when you donate money to politicians/PACs that makes you list your role for compliance reasons.