There are legit free (without capital investment) bitcoin giveaways even on twitter but it's not like the "send me btc and I'll double it" scheme by scammers. The giveaways I'm referring to are competitions like meme, creating songs or other forms.
If a giveaway requires you to do something before you can claim it, then it becomes a task. The real giveaways are run like charities. Again, those who fell for the hackers attics are themselves greedy beings who merely gambled away their hard earned Bitcoin (well, maybe not hard earned after all). Easy come, easy go, states the maxim.