I know several blogs and sites who have written about the semalt referral spam back in 2014 that have gotten legal threats against them. The letters claim trad

I know several blogs and sites who have written about the semalt referral spam back in 2014 that have gotten legal threats against them. The letters claim trademark infringement. They own no trademark in the USA, and there is one in pending status in their own country. Would claiming you own a trademark (yet you don't officially own one yet) be an issue? If you've written about how to block Semalt referrer spam, you're just informing your readers about how to block referral spam (the domain doesn't really matter). So that falls under fair use.