More controversially, many dozens of messages have been sent into Outer Space since 1974. A few have been in the form of physical objects aboard spacecraft, but most have been radio signals aimed at promising stars or star clusters. sometimes called Active SETI or METI (Messaging Extraterrestrial Intelligence). Although the practice continues due to its low cost and relative ease, many philosophers, scientists, and policy experts have come out against the practice largely due to the risk of broadcasting our presence to potentially hostile forces on behalf of future generations that cannot consent (Smith 2020).