+ * The most common threat which Perspectives protects against (a
+ narrow MITM attack, e.g. the attacker controls your gateway) often
+ coincides with the ability of the attacker to filter arbitrary
+ traffic to your node. But in this case, the attacker could filter
+ out your traffic to the notaries (or the responses from the
+ notaries). Such filtering (rejecting unknown UDP traffic, as
+ Perspectives appears to use UDP port 15217) is unfortunately
+ common, particuarly on public networks, even when the gateway is
+ not malicious. This reduces the utility of the Perspectives
+ approach.
+