I use CL and post my phone number. Within Moments of posting an ad, I get spam texts asking me to enter a 6 digit code to confirm that I'm the seller. I researched this and it turns out that people use these code responses to make your number their number for international calling. Then they run up a huge bill on your number while calling all over the world. I usually text, "I'm glad to have your interest, please call me to discuss looking at the part." After they continue text begging me to enter the 6 digit code, I usually block their phone number from calls and messaging. That gets me past the scammers. Once all the 6-digit code scam is done, I get actually interested buyers. CL still works for me, although I list on FB too.