Canon EOS Rebel T6i Instruction Manual page 155

Security
If security settings have not been properly set, the following problems
may occur.
Transmission monitoring

Third parties with malicious intent may monitor the wireless LAN
transmissions and attempt to acquire the data you are sending.
Unauthorized network access

Third parties with malicious intent may gain unauthorized access to
the network you are using to steal, modify, or destroy information.
Additionally, you could fall victim to other types of unauthorized
access such as impersonation (where someone assumes an
identity to gain access to unauthorized information) or springboard
attacks (where someone gains unauthorized access to your
network as a springboard to cover their tracks when infiltrating
other systems).
To prevent these types of problems from occurring, be sure to
thoroughly secure your network.
Using an Eye-Fi Card
When [51: Wi-Fi/NFC] is set to [Enable], image transfer using an

Eye-Fi card is disabled.
Wireless LAN Notes
155