[maxerickson]

I think the temptation to start a car company that markets "Ford" cars is probably less than the temptation to put on your box of bricks that they are compatible with Lego bricks.

If the company doesn't take reasonable actions to protect the mark, they lose control of it.

[detaro]

What does that have to do with how people call actual LEGO bricks?

[maxerickson]

I figured https://news.ycombinator.com/item?id=22276586 made the context clear enough.

Ford doesn't worry about losing their brand. Lego does. So Ford regularly uses the brand as a noun itself, Lego Group asks people to not do that.

[detaro]

The only risk I can see is becoming a generic term for "construction bricks". I don't see how me calling my genuine Lego bricks Legos contribute to that.

[maxerickson]

It's how trademark law is written, use as a noun indicates it is becoming a generic term.