It is not wrong for websites to restrict certain information by their own choice. It is wrong - unconstitutional, even - for the government to force them to do so. You should read a bit about Brandenburg v. Ohio, 395 U.S. 444 (1969) [1] and Hess v. Indiana, 414 U.S. 105 (1973) [2]. (By the way, suicide is not lawless action anyway. Whether advocacy of it is lawless is a different matter, but likely free speech.)
[1] https://en.wikipedia.org/wiki/Brandenburg_v._Ohio
[2] https://en.wikipedia.org/wiki/Hess_v._Indiana