As a qualified product designer (ie I'm fully able to design cases and accessories from scratch) the fan, fan controller and water cooling, aren't really a straight up copy, there's only so many ways you can do those types of things and there's going to be an element of similarity. To me this isn't a major issue.
The caselabs rip offs on the other hand literally look like they've just stuck a sticker on a caselabs case. This is an issue although I do wonder why caselabs haven't gone about things via a legal approach, it's clearly a 'design' which they could have registered in the same way apple have with things like the iPhone and iPad.
I also thought that first image of the tt f51 was a lian li, it's very very similar to their design aesthetic, more so than the fractal in my opinion, from the outside.
The thing is and this is where it sometimes gets a little grey, some companies actually sell 'variations' of someone elses designs under their branding. Silverstone for example sell some external hard drives cases (multi drive ones) which are from another company but use their own branding on it. So without knowing all the details some of the items might actually be 'ok' to be sold under tt branding.