The author points out that an attacker can establish channels to various low-reputation nodes and use them to grief a high-reputation node by jamming up the high-reputation channels and making the low-reputation nodes pay for it. This attack can result in intermediaries losing funds, allowing an attacker to siphon their funds through repeated attacks. The author also mentions another attack in which an attacker charges hold fees and receives a Hashed Time-Locked Contract (HTLC) from the victim but does not forward it. Just before the timeout for the HTLC would force them to settle onchain, the attacker removes the HTLC without forwarding it or blames someone else for its failure to complete. This results in the attacker extracting the maximum hold fee from the victim without the downstream hold fees cutting into their profits. The article highlights the need to address these attacks to ensure the security of the Lightning Network.