You can quote other people’s copyrighted work without permission, so long as commonly accepted norms support the need and the quotation is within the accepted range of common sense. However, for you to do this you have to satisfy the following conditions:

1. The source must be a published work.
2. You have to use it for an appropriate purpose such as reporting, reviewing, studying, etc. within a reasonable range.
3. The commonly accepted norms must agree with the need, and the extent of the use is within the accepted range.
4. You have to indicate the source/origin clearly to the extent that other people can uniquely identify it.
5. Not only must the copyrighted work that includes the quotation be clearly distinguished from the copyrighted work which is the object of the quotation, but there must also be a principal-accessory relationship between the two.
6. You are not allowed to reproduce any copyrighted work without permission, regardless of whether or not there is a description to prohibit unauthorized use.

1. I posted it on a Web page called “Summer Mountains”.
2. I reproduced it on a Web page, its theme being describing the history of Hanshin Tigers over the last 20 years.
3. I posted it on a Web page titled “My sports watching report”. The logo looked good as a symbol of the site.
4. I reproduced it on a Web page which discusses the theme “A championship logo of a professional sports team should clearly indicate whether it is the championship of baseball game or soccer game”.

(a): The “need” may not be agreed upon; (b): The work which is quoting may not be clearly distinguished from the work being quoted; (c): Even if the logo is used only at some part of the Web site, it is likely that the logo constitutes a principal part of the theme. Therefore, (a), (b) and (c) are in “grey” zone. (Not definitely illegal.)

On the other hand, since the logo image is just one of the examples in the article arguing what logos should be expressing, the logo is clearly distinguished from the principal theme and used as an accessory. Therefore, even if it is used without permission, it constitutes a justifiable quotation. As a result, (d) is in the “white” zone (i.e., legal).

When the case is in “grey” zone, the other party (the party whose copyright could have been infringed upon) will not necessarily file a copyright infringement suit. It would not be practical to file a lawsuit when you cannot say that it is definitely “black” (illegal). In particular, if the result of the lawsuit was against you; i.e., it was decided that the case was “white” (legal), it is possible that you could be accused of having committed such offenses as “defamation” (Article 233 of the Criminal Law, maximum term being three years imprisonment), or “false accusation” (Article 172 of the Criminal Law, maximum term being ten years imprisonment).

However, the Internet society includes the US and other countries which are lawsuit societies. Lots of people having a variety of ideas about law suit might see your Web page. Therefore, it is advisable not to use other people’s work if you are in the “grey” zone.