Build up Illegal Line Defenses with Assets Lawfully Lifted Act of 2021 This bill directs certain amounts from the Department of Justice (DOJ) Assets Forfeiture Fund to the deployment of additional border security measures. Specifically, DOJ must report annually on the amount of total deposits into the fund that are derived from Mexican cartels. The bill makes available 50% of that amount for the construction of additional physical barriers and roads near the border to deter illegal crossings into the United States. Additionally, the bill prohibits the release of seized currency or contraband that likely belongs to or supports a foreign illegal trafficking organization while a civil forfeiture action is pending.