Firstly, ceviche is usually made with finely diced meat (most commonly fish); ground meat is usually used for steak tartare. With ceviche, the citric acid causes the proteins in raw meat to become denatured; however, this does not kill most pathogens that could be present in the meat. With steak tartare, horseradish is usually present; it does have some antibacterial properties (one of the reasons sushi is eaten with wasabi), but there is no guarantee that it will kill all harmful bacteria.
I therefore wouldn't eat commercial beef raw, and especially not ready mince (bacteria in red meat are present on the surface, so ground meat could contain pathogens distributed throughout). The reason health & safety recommendations advise against eating raw meat because large-scale farms have a higher risk of infection, and mechanised processing of the meat increases the risk of contamination of the surface.
I don't know about Trader Joe's and what kind of conditions the cattle they source their meat from is raised under (they don't have the info on their website). Of course, grassfed cattle conditions will be better than those in CAFO farms, but its still a large company and I doubt they source from small, organic farms, so there is still a risk, and I think its best to be safe than sorry.
I know Peggy from theprimalparent.com gets her meat from US Wellness Meats and eats it mainly raw; restaurants usually use 'sashimi grade' meat. So, bottom line is that the beef you're eating raw must either be 'sashimi-grade' (though I wouldn't recommend it because it's been treated/processed and you cannot vouch for it being grassfed or organic) or from a farmer/butcher you trust, and the smaller, the better.
And if you are going to eat beef raw, always buy whole pieces rather than mince; you can also trim the exterior which is exposed to oxygen and which would harbor the bacteria. You could also sear the surface of the meat for a few seconds in a very hot pan and then trim the cooked part off.
lots of Paleo love