Not to derail the thread, but I did want to point out that Lomar and Brolaf are the same person ... in essence anyway.

True story. I casted him to act the part of Brolaf back when we were roommates. Good people that Lomar.

Lomar's dad owns a dealership?

(Err, I mean, Lomar does the voice acting?)

Act . . .

You mean he's not like that naturally?

Or by "act" did you mean "act like himself"?

I believe a "tracking pixel" is a small embedded and invisible image used to determine whether a web page is loaded, and from where.

It is unlikely they would be used in game-- simply on the website or in Riot e-mails to determine (as Lomar said) who is accessing their website, from where, and how the person found out about it.

They then use this to more efficiently deploy marketing: so say you found out that lots of new people to your game are coming from Reddit. You can then perhaps increase the advertising frequency and diversity (expenditure) on Reddit and sites similar to Reddit, in the hopes of gaining more players.
(This is a very cursory explanation, Googling "tracking pixel" and "internet advertising" may be helpful.)

Another niche usage is checking whether someone reads an e-mail sent to them. (Potentially useful for warning e-mails, or billing e-mails, and the like.)

As for what would cause arbitration?

This is somewhat entertaining, because in theory Riot's User Agreement gives them blanket power in all regards.

However, there might be some cases they have unearthed relating to e-sports, and people who use the game as their sole livelihood, and thus wanted to "cover their bases".

There may be more, but that's what I've noticed at a cursory glace.

Yes.

I think that people are going against this arbitration a bit too quickly, its no forfeiting your rights, you still have the right to having your case heard, its simply being heard by a local professional instead.
You're still:
Heard by an official, trained legal professional.
reviewed by a non-biased, third party.
In the exact definition of the law, arbitration must follow the same rules as the adversarial system.

The plus side of this is that:
1. You and Riot mutually agree on a mediator, or arbitrator.
2. You wont have to move long distances to legal courts which might not even be in the same state, unless it was agreed upon.
3. Court system is MUCH more expensive and takes an comprehensible amount of time longer than Alternative Dispute Resolution - which FYI, is what arbitration is. Look that **** up first, it helps.

So basically riots forcing you into the better end of the deal, though I know being forced into something seems pretty bad-guy of Riot, I think that they really want whats best for the players and its almost a matter of the players trusting Riot to know what they're doing.
Though; Questions should always be asked, it keeps those with power in check.
I hope this helps somebody

Not a rioter but since I speak both legalese and I'm familiar with the technical side I'll toss in my best reading between the lines.

Both are viable from a technical standpoint since the client main page loads a webpage. From a usefulness standpoint they will almost certainly be using the client since the majority of the playerbase never visits the website and they want the broadest data available.

1) Tracking pixels and cookies take a incredibly negligable amount of bandwidth and are only loaded once per visit. From the users performance point of view they might as well not be there. Riot on the other hand will use a decent amount of processing to manage their monstrous database but you don't need to worry about that.
2) Arbitration is an alternative to a lawsuit. For example (which I'm sure Lomar has dealt with more than once) Buddy-the-troll spends $200 on RP then trolls a whole bunch of games and gets banned by the Tribunal. Buddy-the-troll tries to sue Riot for 'theft of virtual goods' or 'breach of contract' or whatever he convinces a incompetent (or greedily dishonest) lawyer to file. Instead of going to court an ex-judge will meet with them and resolve the dispute (in this case telling Buddy he should have followed the rules and he is SOL).

elaborate please O.o

It's not a program, but evil things inserted into webpages by companies to map which websites you visit over the days, how long you stay at each etc.
http://en.wikipedia.org/wiki/Tracking_pixel