The rally, which began as a protest of the crackdown on the Telegram messenger app, quickly morphed into a protest against Vladimir V. Putin.
https://www.nytimes.com/2018/04/30/world/europe/russia-telegram-digital-resistance.html
https://www.inopressa.ru/article/30Apr2018/faz/tichon.html
http://www.kasparov.ru/material.php?id=5AE6EB2389BD1
http://www.kasparov.ru/material.php?id=5AE63C8183651
https://newtimes.ru/articles/detail/160616
https://nv.ua/opinion/yakovina/doloj-putina-rossijane-vyjdut-na-ulitsy--2467130.html
https://newtimes.ru/articles/detail/160657
https://republic.ru/posts/90662
https://www.svoboda.org/a/29198548.html