Technically, it's legal. It was legalized by the Sony VCR decision.
However, the Sony VCR decision only allows timeshifting for personal purposes, and sharing with close friends and family.
Once you start sharing content with the whole world over high speed connections, it changes from sharing to publishing.
It's a slippery slope and difficult to call at this point, but sharing movies is definitely more protected (by the Sony VCR decision) than sharing music (to which AHRA, a very specific decision, did not really apply).