"Disallowed Key Characters" error from bad cookies

[eluser]Unknown[/eluser]
The CI site I manage is accessed through a proxy server. One of the other sites accessed through the proxy sets a cookie that causes CI to choke and throw the "Disallowed Key Characters" error. I've looked at the code, and it's pretty strict about what it permits, and I was wondering what problems might result from loosening the restrictions a little bit?

[eluser]Derek Jones[/eluser]
I think you might be the same user, but in case you just happen to be behind the same proxy, here's a link to my response to a similar issue an EE user experienced.

In CI, though, there are hooks available prior to the instantiation of the Input class to run through the cookies for you and either alter their keys or unset them.