Well the supposed evidence is from when I asked your guy on Skype how long would it take for funds to be received at the Silk Road if sent. Is this enough evidence that I've been using your service for illegal purposes? Your meagre 42 word provision certainly doesn't exactly draw a line as to what "may" constitute to a contravention of the law and what may not.
Firstly laws are many, and complicated, laying out exactly what is not allowed according to every law under the sun Intersango operates under isn't really possible.
Secondly, you asked them about how long it will take to get your bitcoins to SilkRoad?
Not the smartest thing in the world to do.
Thats like going to a bank and asking them how long to transfer funds to your dealers account (not that I'm calling Intersango a bank, but you know what I mean).
I'm not exactly sure if SilkRoad is illegal or not (probably is in the US, again I don't know IANAL), but I am sure that if it wasn't running on Tor then it would be shut down pronto, and all the information on it would be used to arrest as many people as possible.
Sending bitcoins to SR itself isn't illegal, but the only things you can buy there, generally are illegal, so it seems not only did you violate the TOS, but you went and told them you did.
Word of advice (to all) don't tell your exchange you're sending bitcoins to SilkRoad, or anything
even remotely illegal, it's a bad idea.