"It's actually harder to disallow spaces" Traditionally, when deciding what password characters to allow/disallow, everyone thinks in terms of what to allow, n

"It's actually harder to disallow spaces" Traditionally, when deciding what password characters to allow/disallow, everyone thinks in terms of what to allow, not what to disallow. For example, a system that only allows alphanumeric characters in passwords (i.e. no special characters) would use less code to specify with regex that only a-z,A-Z,0-9 should be allowed, rather than specifying the many characters to be blocked (and even when more complicated options were allowed, code generally still specifies allowed characters, rather than disallowed characters). Therefore I would suggest that websites disallowing spaces in passwords is in fact just that they didn't see fit to allow them, not that they went out of their way not to.