Yes, add these to your MASQ file:
# Deny ICQ Messaging (login.icq.com, icq.mirabilis.com,
www.icq.com)
/sbin/ipchains -A input -b -d 205.188.179.0/24 -j DENY -l
/sbin/ipchains -A input -b -d 64.12.162.0/24 -j DENY -l
/sbin/ipchains -A input -b -d 205.188.153.0/24 -j DENY -l
/sbin/ipchains -A input -b -d 205.188.248.0/24 -j DENY -l
/sbin/ipchains -A input -p TCP -b --sport 4000 -j DENY -l
/sbin/ipchains -A input -p UDP -b --sport 4000 -j DENY -l
# Deny MSN Messaging (messenger.microsoft.com, block port 1863, MSN IP)
/sbin/ipchains -A input -b -d 207.46.183.0/24 -j DENY -l
/sbin/ipchains -A input -p TCP -b --sport 1863 -j DENY -l
/sbin/ipchains -A input -p UDP -b --sport 1863 -j DENY -l
/sbin/ipchains -A input -b -s 64.4.13.0/24 -j DENY -l
# Deny IRC (Block entire 6660-7001 range)
/sbin/ipchains -A input -p TCP -b --sport 6660:7001 -j DENY -l
/sbin/ipchains -A input -p UDP -b --sport 6667:7001 -j DENY -l