Excuse me, if the signatures of QQ and WeChat say to quote other people's sentences or something, is this an infringement? Tell me if you know anything.

The fact of infringement is that the actor uses the copyright owner's works, performances, audio-visual products and radio and television programs in accordance with the conditions of use stipulated in the copyright law without the permission of the copyright owner.

Copyright infringement, without the consent of the author and other copyright owners, is not a case of fair use and legal use, but an unauthorized use of the work, so it is a violation of copyright law.

This kind of infringement may damage the personal rights and property rights of other people's works at the same time. For example, illegally copying other people's works may only infringe on the property rights of other people's works, while counterfeiting other people's works often infringes on the personal rights and property rights of other people's works at the same time.