Yup they are allowed (Steemit is decentralized and free of censorship), there is an API to help developers do creative things with Steemit like write scripts for bots, if you think about it, bots will only help people receive more rewards, and the system seems to disincentivize spam posts (people aren't going to vote them up), and voting on everything is not effective, so bots will need to be programmed to identify quality posts/posters.
Ahh okay cool, didn't realise that. most sites don't allow bots is all. :)
Pretty cool, still learning haha!! x