my_list = [
    ["user1", "192.168.1.1"],
    ["user2", "10.0.0.1"],
    ["user3", "192.168.1.1"],  # Duplicate IP
    ["user4", "172.16.0.1"],
]

unique_ip_addresses = set()

filtered_list = [row for row in my_list if not (unique_ip_addresses.add(row[1]) or False)]

print(filtered_list)