the main issue is that there is a break in the entire chain.
there may be limited spam or none but also you have no one that can post due to lack of mods.
so there is useless posts being made, pretty much as bad as spam anyways, i just posted enough times to be able to ask a simple question.
this forum is built by vbulliten. anyone that would install it would know that it's not some child like freebie with zero security measures, that by default, couldn't just be turned on. on top of that, as a paid member (you cant install vb with out paying) you have one of the largest database for add-ons, many of them being for spam/bot detection and removal.
so yes i do have something constructive, either get a mod online or leave them offline and install an add-on. in 6 years being an admin or super mod, on phpbb or vbulliten i have only had but 2 spam threads to attend to.