Ask YC: agressive non-compete/non-solicitation agreement

I'm about to sign on to a NYC-based startup on Monday, and this part of the non-compete agreement they sent me raises a flag:

  Covenant Not to Compete: The Employee agrees that for a period of twenty-four (24) months following termination
  of the Employee’s employment with the Company for any reason, the Employee will not, directly or indirectly, own,
  manage, control or participate in the ownership, management or control of, or be employed or engaged by or
  otherwise affiliated or associated as a consultant, independent contractor or otherwise with any other corporation,
  partnership, proprietorship, firm, association, or other business entity that is engaged *in any manner in the 
  Business of the Company in any market (including the Internet market)* located in the United States as well as
  outside the United States in which the Company markets any of its products or services.

Am I right interpreting this as saying that I can't work for internet related companies if I leave the company? Is this unenforceable boilerplate legalese that I shouldn't worry about, or something to discuss?

Another provision which bothers me is one that says I won't (for 24 months) "Employ, assist in employing, recruit or otherwise associate in business with any present, former or future employee". Is this something that's worth challenging?

I don't fully understand some of the other concepts in the agreement - things like definitions of "Reasonableness" and "Toll Period", which seem to be based on particular cases or laws - what is a good place to read up on this?