First picture is one of those RONI (or something like that) carbine conversions for Glocks fitted with a weaponslight and a new stock. Realy pointless weapon, IMO.
http://www.imfdb.org/wiki/Nikita_(20...ctical_RONI-G1
Secind picture is an MP5A3 with an ELCAN and somesort of thing on the back of it, plus what may be a light on the front.
Third is an M4/HK416 with a 10" barrel, suppresser quad rail, and foregrip. It's also lacking a rear sight of any kind. Also an MP5A3 like in the picture above it, but lacking the ELCAN andwith e the flashlight.
Fourth is some sort of AK. It's not an AKM and I can't see the foresight well enough to determine if it's a Type 56.