In 1996, the Department of Finance did announce certain measures to tighten the migration rules for individuals, including trusts, who emigrated from Canada, and these received royal assent in 2001 and were retroactive to 1996.
Essentially, under the new rules, people who leave Canada must calculate their taxes as if they had disposed of their property, other than certain taxable Canadian property, and they can either pay that tax immediately or else, as you noted, they can post security for that amount. Depending on whether they're an individual--a person--or a trust, there are certain forms they have to complete and certain information requirements they have to provide to the agency. And when they emigrate, they need to identify all the properties they hold.
We do have a system that tracks this information and tracks each of the properties they reported in the year of emigration. Anybody who chooses to defer payment of the tax owing is required to provide security before the due date of the return or to contact us to make an arrangement.
These accounts are in fact monitored on a yearly basis, and each and every year we issue letters to remind the taxpayers, after emigrating from Canada, that if they dispose of any properties, they should notify the Canada Revenue Agency of those transactions.
So that kind of monitoring and tracking system does in fact exist.