The true answer is yes and no.
Yes as to any fonts that are original and provided as either shareware or freeware. No if they are renamed clones of original copyrighted work ... but yes until such time as the true copyright owner challenges them.
Confused? Blame the US Trademark and Patent Court. (Yes, you've got me started now
).
In 1988, the court ruled that the latin alphabet is in the public domain and that no design of any alpha-numeric character was protected under patent law. The court further ruled that the only thing protectable was the trademarked name of a font.
From that ruling a new industry was born where all you had to do was to open a font in Fontographer, enter a new name, enter your own information under Copyright, regenerate the font and start selling it. The whole process takes less than two minutes. The PC Magazine Product of the Year in 1992 was a 120 font collection called Typecase from a company called Swfte (pronounce that one). They sold 7,000,000 copies at $59.00 each. Typecase was comprised of 120 renamed fonts from the Bitstream library.
Within a couple of years Bitstream declared Chapter 11 bankruptcy and as part of their reorganization sold unlimited lifetime rights to Corel Corporation for about 700 of their fonts for $1,000,000. Other type developers including URW, Letraset, Monotype, Berthold went under and were acquired by more diversified companies.
Finally, in 1998, Adobe Systems won a case against The Learning Company wherein the court upheld that any glyph (a vector alpha-numeric character in this case) was a mathematical formula and could therefore be protected. The Learning Company, publisher of KeyFonts Pro (under license from Southern Software) ended up paying Adobe $1,000,000 in damages and agreeing to never again market any product which competed with any product sold by Adobe.
So after 10 years of hell for the design foundries, there was finally a turnaround. But in the meantime, the internet had become viable and free font sites were a successful business model. Many of the original designers had left the business and it has and will continue to take many years for the current owners of the copyrights to find and challenge the giving away of their designs.