Is 'Comment SPAM' illegal?

Below you will see an example of 'Comment Spam'; Annonymous seems to "like what we're doing" (really), and would like Compliance speak readers to have a look at their 'autocad' site. Mmmm. Lets simplify things by assuming that the poster (or instigator) resides in the UK. Unlikely I know. Would this be illegal? Has the poster breached the Privacy and Electronic Communications (EC Directive) Regulations 2003? Is this unsolicited 'electronic mail' for the purposes of direct marketing? I think so! Is it illegal? Probably not. Comments made to Compliance speak are in effect 'email', and compliance speak is operated by a corporate subscriber. The responsibility of the sender is therefore to identify themselves AND provide a vaild opt-out mechanism. A little bit of surfing demonstrates that they fulfil both of the obligations above; so legal! Now to see if they honour my request not to send unsolicited dm messages to compliance speak. Fat Chance!