What are the legal ramifications of streaming pirated content? Could you cache popular content to preserve downstream traffic? Or is that the loophole? This plus content aggregation/browsing.. hmm..
If so, then high-profile and particularly-irritating pirates will be targeted, and if the laws don't specifically make it illegal then they will be twisted to enable prosecution anyway.
In the United States, prosecutors routinely fabricate financial returns for piracy, that way it's a felony instead of a misdemeanor. They do this by making the argument that the movies they downloaded for personal viewing constitute financial proceeds.
When such a thing is not only possible, but standard operating procedure, asking about the legal ramifications are silly. You're probably still safe just by being part of the herd, but they've been known to single out people to make examples of too.
For you, it is copyright infringement. But it's hard to catch you. I guess you are vulnerable to joker.org giving you up if they get subpoenaed, if they keep records.
For joker.org, that depends on how they are classified. It probably does not qualify for a transitory network safeharbor because 1) if it's servers are uploading it is giving the file to more than one person and 2) joker.org is arguably modifying the content by assembling it into a stream. Though I could be convinced it isn't modifying it just by streaming it. If they are caching, it would also bust their safeharbor.
If it is classified as a §512(c) site, it has a better argument actually. Though I don't see a DMCA agent listed on the site.
"The court said: Whether looking at a cached copy of protected content, without downloading or printing it, amounts to infringement. Lower courts held that it does, a finding unanimously rejected by the Supreme Court.".
A download would classed as anything that didn't satisfy those conditions. So if you're storing something for the purposes of making use of it later it would fall outside the exception as it would not be temporary or transient.
Technically your browser downloads content of course, but provided the content is only viewed whilst you are in the browser and not retained following the end of your browser session (or were merely retained in your cache), this would not constitute a download for the purposes of putting a user outside the exception to infringement under Art 5(1).
[1] http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:...
See Richard O'Dwyer http://en.wikipedia.org/wiki/Richard_O%27Dwyer