Within the AFOL community there are some subjects which are controversial. While many AFOLs decry attempts to limit a persons freedom of expression in what they can build, anyone building MOCs on such subjects should be aware that they may be offending other AFOLs or even people outside the LEGO community.
Nominally a fan developed theme Bonktron is an elaborate joke whereby space vehicles are built in the shape of human genitalia. Response on LUGNET to the first Bonktron MOC the Throbtastic Jismatron X3 was generally positive although it was not without protest. Responses to subsequent models in the theme were mostly received far more poorly and were often considered to be designed purely to cause trouble without any genuine humourous intent. The theme (including mention thereof) was banned from Classic Space Forum.
BrickMedia / Bricks Magazine
Bricks Magazine was announced  in January 2003 as a fan created magazine about the hobby, by BrickMedia, LLC owned by Matt Gerber. It was promoted heavily on AFOL websites and at Brickswest 2003 by Matt Gerber and Tim Courtney, and endorsed by several high profile AFOLs.
In March 2003, it was announced  that BrickMedia would be offering charter subscriptions for the new magazine . Many fans took up this offer, but the publication was delayed at least once . By July 2003, the venture had failed. No magazine was produced, and no money was returned to subscribers.
Matt Gerber has not posted publicly in the LEGO community since, and it has been speculated by many that he disappeared with the money , but nobody with any knowledge of the details is prepared to make them public .
In 1996 the Polish artist Zbigniew Libera designed and built sets complete with boxes bearing the LEGO logo. His subject was Nazi concentration camps. The LEGO Corporation had given Libera the bricks for free without inquiring about the theme of the artwork as part of a program that provided many Eurpean artitsts with LEGO bricks. This led Libera to controversially include a notice on his boxes saying "sponsored by LEGO Systems". LEGO insists that they did not endorse his artwork.
The Jewish Museum in New York exhibited these sets in 2002 as part of an exposition entitled Mirroring Evil: Nazi Imagery/Recent Art. Critics charged that Libera's sets trivialize the Holocaust. Defenders argue, however, that the LEGO sets mirror the evil-minded ingenuity required to construct the concentration camps as instruments of terror.
- See also a collection of articles on the project.
This is a MOC created by Richie Dulin involving a Spiffcraft-like spacecraft shaped like a swastika. The Schpiffkraft Hakenkreuz (SH) caused a long debate on Lugnet with some people decrying the concept and others defending it.
LEGO has often faced criticism that their sets and marketing show a lack of diversity. Accusations of sexism, racism and colonialism have all been made at one time or another.
In 2014 the environmental group Greenpeace attacked the long-standing partnership between Shell and LEGO. While the basic material used to create modern LEGO products is ABS, a petroleum product, the ad did not directly criticise LEGO except by association.
- see also: Everything is NOT awesome.
In 2016 an article was published on the question: Have LEGO Products Become More Violent? by Christoph Bartneck an academic and author of the minifig catalogues. Bartneck demonstrates that indeed they have.