Adblockers: depends (the answer isn't clear). But that is a much more general debate (applies to all sites), and one that doesn't belong here.

JDownloader: no. IIRC, it's actually officially sanctioned by the hosting sites. For example, the first time you download from any site, you're required to check a box in JDownloader saying you agree to that site's TOS, which means that JDownloader obviously isn't in violation of the TOS. And JDownloader very prominently displays links to premium account signups, so I'm pretty sure the sites like it. Like icebraining said, their primary revenue stream was premium account fees. Otherwise, they would be constantly changing the layout to break JDownloader support.

I am having my doubts on if JDownloader is actually sanctioned by the hosting sites. At least whenever I have to use it, it takes quite some time to update its ability to work with certain one click hosts. I also always suspected that the TOS agreement is some way for the JDownloader developers to transfer the responsibility of breaking the TOSes towards the user.

Don't get me wrong, I am a regular user of these kinds of software products, but just by their incredible amount of supported download hosts it seems that they are at best "tolerated". But I guess the tolerance level is also quite large in this "sector" as long as it doesn't target their premium account business.

> it takes quite some time to update its ability to work with certain one click hosts

This might have more to do with the quality of the software (a desktop Java app? in 2012?) than anything else. I would love for someone to come along and make a JDownloader clone using GTK or Qt.

That said, you're right in that JDownloader's in a gray area. They can't have possibly gained approval from all those sites.

I am affiliated with one of the sites JDownloader supports, and they certainly did not ask us for approval. Whatever you try to stop them is futile, since they can react quickly.

JDownloader breaks our business model since we don't have premium accounts, but in the end you have no other choice but to accept that some people are leechers.

So, please don't think you're doing good when using tools like that and advocating their use.

>the first time you download from any site, you're required to check a box in JDownloader saying you agree to that site's TOS, which means that JDownloader obviously isn't in violation of the TOS.

That doesn't follow, at all. TPB could make me check a box saying, "I agree not to commit copyright infringement" every time I want download something, but that doesn't change the nature of what I'm doing.

Ah, so ethics only matter when it's convenient.

I don't remember MU having third-party advertising, but if it did, it was minimal. They make their real money from paid accounts, which give more features.

Besides, even if MU had them, ads nowadays are paid-per-click; services only make money if you actually clicked on those ads. There's no real difference between using JDownloader vs going to the web page but not clicking on any ads.