Not sure eavesdrop is the right word, since ISPs throttle all sorts of traffic by inspecting it such as torrent, let alone TOR.   I suppose we could argue that in signing up for an internet connection, deep in the ISP’s small print, we consent to that behaviour.  Is it really true that consent has to be sought by every router on the way?

Inspecting packets for obvious things like denial of service attacks and brute force logins would seem very legitimate to me and I doubt that the law would be such an ass, since we cannot gain consent.

I know there is a fine line but looking at how packets are behaving and looking for repetitive logins is not the same as watching the content and censoring that.  Then an exit node could only inspect what EXITS onto the internet.

Gerry 

From: tor-relays [mailto:tor-relays-bounces@lists.torproject.org] On Behalf Of Gareth Llewellyn
Sent: 12 June 2016 18:38
To: tor-relays@lists.torproject.org
Subject: Re: [tor-relays] Filter Tor Exit Node for blatant attacks on servers

On 12 Jun 2016 5:49 p.m., "Jonathan Baker-Bates" <jonathan@bakerbates.com> wrote:
> But along the way I asked some others about the legal implications of doing what the ISP had asked. The rough consensus was that in the UK at least, I would only be able to evesdrop on traffic once consent had been given by those being monitored. Otherwise I'd be illegally wiretapping and open to prosecution. But it was far from clear what would happen if somebody took me a court!
>

Indeed the Regulation of Investigatory Powers Act 2000 and the Investigatory Powers Bill contain offences relating to surveillance of traffic without a warrant / permission etc. (Caveats etc apply)

> On 12 June 2016 at 16:12, Dr Gerard Bulger <gerard@bulger.co.uk> wrote:
>> Once TOR
>> exits attempts any filtering where would it stop?   It is a slippery slope.

FWIW one of the reasons we have the "pirate" blocks (in the UK) is that the High Court Judge (Hon. justice Arnold) in the case was informed that the ISPs in question had the ability to block sites (e.g. Cleanfeed) therefore it was possible for them to block more.

Had this ISP level censorship technology not existed then we wouldn't be in *quite* the situation we are now.

>> It is more than embarrassing to run an exit node and get abuse complaints
>> about persistent and repeated attacks on an IP. The intent is clearly
>> criminal.  VPS providers in the UK are increasing intolerant in receiving
>> such complaints.  The whole VPS can be closed down by the ISP/VPS provider
>> not forcing a closure of the TOR exit.  Fewer ISPs will allow you to install
>> an exit node at all.

This is one of the reasons why I started a UK ISP (AS28715) - I now run UK exits and don't have issues with them getting shutdown because the ISP got cold feet / got bored of abuse emails / complaints from other customers (entire /24 blocked by anti-tor blacklists) etc etc.

Good ISPs don't deploy web filtering, transparent proxies or IDS' that interfere with traffic. IMHO well behaved Tor Exits shouldn't either.