There is a fine line as it relates to passion and nostalgia when it comes to properties owned by big corporations. Fan efforts to pay tribute and keep alive the things they love are fine, and probably even appreciated by those companies, until there is the loss of potential revenue involved. While big brands vary on how aggressive they are in pursuing legal action against what might be well-meaning enthusiasts, they tend to be very litigious when it comes to concerted efforts at what they see as exploitation of their intellectual property.
Nintendo is filing a lawsuit in Arizona against a company that it asserts is infringing upon copyrights of many of its old games. In the lawsuit, Nintendo is accusing LoveROMS and LoveRetro of distributing thousands of its games and the images related to them through ROMs and emulators that enable users to play old Nintendo games through their computers. And the company isn't holding back in trying to shut down the site and discourage copycats, asking for $150,000 in damages for each instance of copyright infringement and $2 million for each case of trademark infringement, as well as any records the sites have pertaining to revenue they may have generated from their distribution of the games.
Nintendo also makes the point in the suit to note that the operators of the site appear to be individuals with a detailed knowledge of Nintendo's intellectual property and the video game industry as a whole, seemingly to differentiate that this endeavor would appear more intentionally malicious than the average fan attempting to keep Punch-Out alive for future generations. They also distinguish LoveROMs and Love Retro as "hubs for pirated video games" which might explain the fervor and fury of the legal action taken, when a simple cease and desist might otherwise work in other instances of more contained infringement.
The relationship between fandom and commerce can be tricky and tempestuous, and the balance between protecting IP and allowing for creative fan projects that might approach the line of infringement but serves to build loyalty is something that every entertainment brand has to consider. But in cases that can easily be considered as copying the work of those companies, fans should steer clear to avoid legal entanglements.