Not all but you can see most of those scam giveaways can be seen on social medial platform so better to review it first before joining. Report if you can see any suspicious giveaways and its good that you share this information as well so your friends wont become a victim. Scammers will not stop from doing this, they make big money on this and the only way to prevent yourself from becoming a victim is to educate and invest on yourself.