Modern PCs and even smartphones have enough performance to use neural networks to create messages with hidden information. One of the algorithms The system generates the "natural" text of the announcement about the sale, for example, technical literature. The text of the message is formed by the neural network so that the required positions contain the characters that make up the encoded message. The message is then posted on the bulletin board. If you publish PDF files in online libraries, then this method of transferring information is even easier. Another way to use the technology is to design advertising posters, in which the data is included in the background created for the advertised item. But these are the simplest options for which countermeasures can be provided. It is interesting to use global online services or (and) neural networks for "intuitive" coding.