But yeah I've seen so many people getting scammed, and I almost fell to a scam once but that was in game, nto on JSP but my friend almost got scammed. and tons of people are getting scammed.
and the thing is that scammer are using multis so blocking an Ip might not be enough.

and I was wondering if there is any way to block mac adresses from a certain computer, kind of like how you can do it in a router or modem.

As far as I know MAC addresses are trackable only at LAN (with ARP).

Voted no anyway, would be crazy..

Really? I didn't know that. so there is no way to block people via MAc address, and why No as long as you're a legit trader you shouldn't be afraid.

its possible to change the mac adress

I know it is but if you change it and its been used by somebody else then it won't work so changing Mac address is very dangerous if you have no idea of what you're doing