We see it all the time…

Fraud.

If you receive an email warning you to “upgrade your account” or threatening that your account will be deactivated unless you click some link, it is always fraudulent. These messages are from scammers trying to steal your UTORid + password or your banking details.
The University will never send an email asking for your UTORid and password. Not for any reason. Guard your UTORid + password. It should only ever be entered on the University’s familiar authentication pages. Always take note of the web address at the top of your browser – it should say “University of Toronto” in green and begin with https.

Hard drives fail. USB memory sticks fail.

The disk inside your computer will fail; it is simply a question of when. Your Windows or Mac computer has built-in backup software. Use it. Keep your entire hard drive backed up so you can recover from a catastrophe.
Your trusty flash drive will fail; it is simply a question of when. You likely will not have any warning. Save your important files on at least two devices at all times. Store your important documents online with a service such as OneDrive or Dropbox.

Windows computers absolutely need anti-virus software.

Viruses and malware can steal personal information, destroy data, and turn your computer into a criminal Internet zombie. Install an anti-virus program and keep it up-to-date. We recommend Microsoft Endpoint Protection (free for University-owned PCs) or Microsoft Security Essentials (free for personal machines). For Mac, we recommend the free Sophos Anti-Virus for Macs. If your browser is misbehaving (broken home page, popups) scan with an anti-malware package: MalwareBytes (Windows and Mac).
Install operating system updates promptly on Windows and Mac. Keep installed software up-to-date, especially web browsers.
DO NOT run Windows versions older than Windows 7. Do not install Flash. Do not install Java. Do not install iTunes/QuickTime. (If you insist, it is critical that they are kept up-to-date.)

Stuff gets lost/stolen.

If you work with sensitive files such as research, student, or administrative data — and particularly if you use a laptop — University policy may require that you encrypt your hard drive, external drives, and USB sticks. Encryption makes it practically impossible for anyone to access the data without your password. It’s easy to do with the built-in FileVault on Mac, and BitLocker on Windows.