Update: Twitter restored Sea Lion Club and apologized for the error.
“The URL [sealion.club] was mistakenly flagged as spam, by an outside organization that tracks spam sources. We have restored access and apologize for the error,” said a Twitter spokesperson.
After Twitter banned alt-right provocateur Milo Yiannopoulos this week, some Twitter users were a little salty at the crackdown on free speech and began looking for an alternative.
One of those alternatives is now tougher to find. The microblogging site, sealion.club, a small Twitter clone popular with Gamergate types, seems to have been added to Twitter’s spam filter. Twitter does not let you tweet the URL or add it to your bio. Those with the URL already in their bio appear to have been shadowbanned from Twitter.
Shadowbanning is when an account still exists, but doesn’t appear in other people’s timelines and the tweets from the account don’t show up in mentions. Twitter does not publicly acknowledge the practice but it is fairly widespread on the platform, especially for those with controversial, often far right, opinions.

When Twitter user @conrad1on tried to tweet at me to let me know he had been shadowbanned, it did not appear in my mentions. Only by going to @conrad10n’s profile could I see his tweets.
.@WilliamUsherGB @William__Hicks Here's some evidence of Twitter shadowbanning in case you need it. [1/3] pic.twitter.com/1lR0qzDbVU
— conrad1on (@conrad1on) July 20, 2016
.@WilliamUsherGB @William__Hicks If you even get any of this.
— conrad1on (@conrad1on) July 20, 2016
Not surprisingly, the founder of Sealion Club, Hope McKenna, is not happy with Twitter for actively punishing users of her site, which has been around for about a year and has some 150 users. “The blacklisting was just annoying, as an Objectivist I feel a company should be able to do whatever it likes within the bounds of rational laws,” she said. “But as soon as I discovered users who were trying to share the link with friends were suffering negative consequences, the shadowbans, I’m pissed.”
Twitter user @MrShikaki made a shortened URL to link to Sealion Club, but when he tweeted it he was shadowbanned along with a few others who tried it. According to McKenna, about seven known accounts have been shadowbanned so far.
Ready for some fun? sealionclub is blacklisted
So @MrShikaki made a shortlink
People post it, they get shadowbanned pic.twitter.com/nBgPuSguH8— What-Is-This-I-Can't (@HopeStillFlies) July 20, 2016
Some of the users eventually had their bans lifted although others still remain in the odd Twitter limbo.
Shadowbanning is a tool usually designed to combat spambots. By muting them to the rest of the site, the spambot will continue operation without its creator knowing it has been made useless.
But applying this filter to a site like sealion.club and punishing its users is a grave misuse. Twitter has not returned a request for comment, so it is not clear if the blacklisting was a mistake.
Twitter has been under fire recently for attempting to silence conservative voices on the platform. The permanent ban of Milo and Robert Stacey McCain has raised some questions about how objectively Twitter applies its rules, and whether it’s quicker to banish voices on the right than the left. Going after a small club of Gamergaters would appear to be new evidence of selective policing.
Follow me on Twitter @William__Hicks.