Some 800,000 people have been locked out of their MyAccount service with the Canada Revenue Agency after the government agency revealed on Friday that usernames and passwords may have been accessed by “unauthorized third parties.”

Local chartered professional accountant Doug Kirby says it’s the second such incident in just a few weeks.

Less than a month ago the CRA locked out 100,000 people, resulting in “absolute chaos.” He says it took “days and days and days to get through to CRA to talk to somebody to try to get you out of that problem.”

Those 800,000 people may have issues with their taxes, but things get even more complicated for those applying for government programs through CRA.

Kirby advises anyone affected by the situation to “get hustling” to get it rectified. He also advises people to change their passwords and usernames if necessary.

CRA discovered the usernames and passwords for sale on the dark web and locked the accounts as protection. However, Kirby warns, if you use the same username and password for your banking for instance, then they’re also compromised.