Roblox is rolling out virtual billboards with video advertisements, the gaming platform said on Wednesday, in its latest move to draw revenue from its games that are mostly free to play.

Roblox has long been the target of criticism for its security protocols. The controversy has also encouraged so-called vigilante users of the platform to seek out and expose child predators.

Roblox’s stock dropped amid growing concerns over the lack of security measures to protect its large number of child users.

Roblox announced Monday that it’s launching the first iteration of its 3D model, dubbed “Cube,” to allow creators to create 3D objects using generative AI.