Friends with anarchist Emma Goldman, he founded the FSL with several progressives in 1902, among which was Lincoln Steffens, who famously said "I have seen the future, and it works!" in regards to the newly emerging Soviet empire after a trip to Russia in 1919. Later on, Schroeder's ideas even became influential with Havelock Ellis, who was one of the founding members of England's Fabian Society.
Most importantly though, the FFRF states that the FSL was a precursor to the ACLU. I find it so interesting how all of these people and groups, that all the dots end up being connected. It always ends up coming full circle. One group learns what does and doesn't work, then shuts down(or renames itself) and the new group takes what was learned and implements it. Anyways, Schroeder confirmed his beliefs three times, on page 135 and again on 136 of "Free Speech for Radicals":
(135) I will state now that it became public that I was a Socialist and member of the Free Speech League.
(136) I was employed at the Helping Hand Home and had been there about a year. Third, that I am not an I.W.W. I am a Socialist and member of the Free Speech League. Fourth, I did not disturb the peace, and offered the proof. Part of my papers was taken from my clothes when these were returned to me.
(136) Now, on March 15, 1912, she came back again and asked me if I still persisted in being a Socialist and member of the Free Speech League and reading their literature and taking part in the free speech fight. Yes, I do persist in being a Socialist and believe in free speech. Then, she said, my services were no longer wanted, and she said I could vacate at once.
The man is more than free to believe whatever he wants. My preference would be for their radical beliefs to be widely known as these people thrive on living in the shadows - put it in the headlines and let people see how whacked out they are. But that said, I read through parts of the book, and I have a suspicion that many of the alleged actions on part of 'them pigs' and other authorities are trumped up to make the radicals(and they know full well they're radicals) victims and martyrs. Also, parts of the book seemed pretty standard fare for what the ACLU does today. They'll defend anybody who's subversive of American beliefs and traditions, but if those who defend liberty find themselves in a bad spot, the ACLU is usually nowhere to be found.