Not a bot exactly. A number of monks here are involved in a research project to measure the effects of online voting systems over the long term. They chose the monastery due to the longevity of many of the monks. You are one of the subjects chosen to be persistently downvoted. Sad to say, this choice wasn't arbitrary.
Each of these monks (and they are not who you might think they are) runs a script which simply logs in for them, scans the Newest Nodes and votes on them according to a set of rules. This is why you often see some nodes, not just yours, getting one or two votes almost immediately.
Every few days, another script runs and gathers all the nodes that have been voted on, then divides up the links to the team for psychological analysis. They have been doing this for years.