In e.g., http://arxiv.org/abs/arXiv:0712.3526 the author claims:
Since the massless higher-spin field theories involve infinite-dimensional gauge symmetries, one expects that such theories may be ultraviolet finite.
This statment is connected to the statement that one believes that Vasiliev theory is UV-complete.
How exactly is the connection between infinite gauge symmetries and UV finiteness and why do we believe that this is true?