@Cookies and cream
"But things like flash, active X and Java vulnerabilities, and trust across the domain is compromised a bit."
Java vulnerabilities? I think Java applets (the only ones that actually run client-side) are the only "plug-in" stuff that actually has a security sandbox that disables *any* access to the local machine's resources! In fact, you need some weird stuff like permission policies and signed code to actually get any kind of access on the client's computer.
JavaSCRIPT, on the other hand, sucks donkey balls and has more security holes than Swiss cheese.
However, I agree (and most of us do) on the fact that domain redirection is:
1 - tampering with DNS, a "basic" internet protocol; breaking RFC's in the process
2 - if the "response" is for an existing domain, this is domain hijacking, which is definitely illegal akin to tresspassing
3 - It opens up nicely an XSS backdoor, which must have malware/worm/botnet writers getting a nice entry point
4 - the ISPs themselves have opened up a pretty nice target for DoS, DDoS, and other kinds of attack. And not just from crackers, but I'm pretty sure some perfectly legal users would like to slam the sites behind this domain hijacking.
Because of point 2, I really hope that those responsible for PiTMA will end up in PMITA ;)