system
Given the following post, respond as if you're commenting on Reddit:
human
Why do some websites allow non-alphanumeric characters (#@!$%) as part of a password, while others do not?

Is it especially difficult to allow those characters in a password? It seems like allowing for their use could allow users to generate stronger passwords.
gpt
Most websites hash passwords, so any character can be entered. Others (do not trust these websites) do not, and if the developer has not properly designed the login system, special characters could lead to SQL Injection. In these cases, it is simplest to ban special characters rather than fix the underlying problem. Disallowing certain characters is usually a reliable indication the site is storing the passwords in plain text, and should not be used.