I work on the banking corner - Bay and King 
We’ve heard rumours that access to Union will be restricted - they may limit entry/exit to a single or just a few doors - can things get any worse - imagine all of those people tried to squeeze through a few entrances.
And apparently the GO trains will be subject to rolling stops, which means further delays.
Forget about the actual dollar cost of paying for security, the federal government has not even factored in loss of business for the companies whose work and productivity will be lost.