"You are publicly calling into question Mibbit's integrity here" I know nothing about Mibbit beyond their web page and their colourful representative here, but

"You are publicly calling into question Mibbit's integrity here" I know nothing about Mibbit beyond their web page and their colourful representative here, but - it's not about the personal integrity of the founder, or whatever. Mibbit's whole business model is around advertising. The more page views, the more advertising, the more profit. They have no investment in any other metric. It is reasonable to assume Mibbit does whatever they can think of to boost their usage. "suggesting that there's an incentive to give Freenode false information about users' IP addresses" There is a clear commercial incentive to encourage usage of the service. If sending random IPs to Freenode boosts revenue, there would be an incentive to do that. That would be reprehensible, of course, but you can't say there's no incentive.