You must be knowing ASA/Pix(version7) has default classes for this type of traffic
Security-525(config-pmap-c)# sh run all class-map type inspect http
!
class-map type inspect http match-all _default_gator
match request header user-agent regex _default_gator
class-map type inspect http match-all default_kazaa
match none
class-map type inspect http match-all _default_msn-messenger
match response header content-type regex _default_msn-messenger
class-map type inspect http match-all _default_yahoo-messenger
match request body regex _default_yahoo-messenger
class-map type inspect http match-all _default_windows-media-player-tunnel
match request header user-agent regex _default_windows-media-player-tunnel
class-map type inspect http match-all _default_gnu-http-tunnel
match request args regex _default_gnu-http-tunnel_arg
match request uri regex _default_gnu-http-tunnel_uri
class-map type inspect http match-all _default_firethru-tunnel
match request header host regex _default_firethru-tunnel_1
match request uri regex _default_firethru-tunnel_2
class-map type inspect http match-all _default_aim-messenger
match request header host regex _default_aim-messenger
class-map type inspect http match-all _default_http-tunnel
match request uri regex _default_http-tunnel
class-map type inspect http match-all _default_kazaa
match response header regex _default_x-kazaa-network count gt 0
class-map type inspect http match-all _default_shoutcast-tunneling-protocol
match request header regex _default_icy-metadata regex _default_shoutcast-tunneling-protocol
class-map type inspect http match-all _default_GoToMyPC-tunnel
match request args regex _default_GoToMyPC-tunnel
match request uri regex _default_GoToMyPC-tunnel_2
class-map type inspect http match-all _default_httport-tunnel
match request header host regex _default_httport-tunnel
!
So you use the following commands to block for example Kaza
policy-map type inspect http filterp2p
Security-525(config-pmap-c)# policy-map global_policy
Security-525(config-pmap)# policy-map type inspect http filterp2p
Security-525(config-pmap)# class default_kazaa
Security-525(config-pmap-c)# drop-connection log
see if this helps !
