Font licensing is a very contentious issue. While it is true that there is a wealth of freely available fonts, the chances are that the fonts are ``ripoffs'' in some sense, unless they come with a license indicating otherwise. The issue is made more confusing by intellectual property laws regarding typefaces. Basically, in the USA, font files are protected by copyright, but font renderings are not. In other words, it's illegal to redistribute fonts, but it's perfectly legal to ``reverse-engineer'' them by printing them out on graph paper and designing the curves to match the printout. Reverse engineered fonts are typically cheap and freely available, but of poor quality. These fonts, as well as pirated fonts are often distributed on very cheap CDs containing huge amounts of fonts. So it's not always easy to tell if a font is reverse engineered, or simply pirated. This situation creates an enormous headache for anyone hoping to package free fonts for Linux.
Perhaps one of the most offensive things about the nature of font piracy is that it artificially debases the value of the work that type designers do. Pirated fonts invariably are bundled en masse onto these one zillion font CDs, with no due credit given to the original designers. In contrast, what is commendable about several legitimate font foundries is that they credit their designers.
There are many differing opinions on this issue. See typeright for an explanation of the case in favour of intellectual property rights. Also, see Southern Software, Inc for another opinion -- but don't buy any of their fonts! Their Type 1 fonts (poorly reverse-engineered Adobe fonts) do not have AFMs, and are thus unusable.