Advice Security Experts Rated Useless and Harmful

Note: The evaluation of the following advice as "useless" or "harmful" does not necessarily reflect the opinion of the researchers. Please see Redmiles et al. 2020 for more information.

All advice is of the form "You should...":

Useless Advice

consider opening a credit card for online use only [all experts agree]
file taxes early[all experts agree]
let your children teach you about the Internet too [all experts agree]
use an unbranded smartphone [all experts agree]
ask people to remove your personal information and photos
be aware of your online reputation
bring proof-of-purchase for computer equipment when traveling
carry laptops in something other than laptop cases
change your respondentname regularly
contact police or authority figures in case of a cyberattack or cyberbullying
create keyboard patterns to help with remembering passwords
create pronounceable passwords
disable and/or limit caching
encourage the positive sides of the Internet with children and friends
install software in phases
keep the computer in a common room in your house if you have children
not meet up with people you've met online
not use credit or debit cards online
not use encryption when sending e-mail to a listserv
regularly search for your name
shut down your computer
store passwords in a file
try alternate urls to avoid censorship
understand new features before you try them
upgrade your email provider
use a load balancer

Harmful Advice

base passwords on upcoming events
buy devices with passwords, preferably passwords that you can change
change passwords often
clear your cookies
create a new email address if your last one is compromised
create keyboard patterns to help with remembering passwords
download a filtering software to prevent website access
draw shapes on your keyboard to generate passwords
feel comfortable making weak passwords for sites thar don't keep personal info
install firmware on mobile devices
isolate iot devices on their own network
keep sensitive information on removable storage media
lock your sim card in your smartphone
not change browser security settings
not change your passwords unless they become compromised
not download or execute any files
not identify yourself to websites
not open attachments from unknown senders
not respond to or retaliate against cyberbullies
not send or forward files you haven't scanned for viruses
not shut down your computer
not use a password manager
not use encryption when sending e-mail to a listserv
not use extensions or plugins
obfuscate something meaningful to generate a password
protect your computer from power surges
remove improper and/or sensitive information from the web
store passwords in a file
store passwords properly
transfer sensitive files to network shares
turn off automatic downloads
use different personas online
use filters in email
use less common software
use private search engines
use tor
use tracking applications
write down passwords on paper