On the client side, Second Life requires its own software, and that software requires that certain ports (443/TCP, 12035/UDP, 12036/UDP and 13000-13050/UDP) be opened on your firewall.

More broadly, Second Life is treading new intellectual property ground, which has raised issues of ownership, copyright and even personality rights. Lawyer Mark Bragg has been suing Linden Lab for nearly two years over a questionable land deal. Lawrence Lessig's recently released new edition of Code uses Second Life activity to illustrate various thorny IP issues.

A recent griefing incident at an SL event held by Ailin Graef/Anshe Chung led to Graef's real-life legal representatives making copyright violation claims against journalists covering the attack. And a hack called CopyBot struck at the heart of the economic system, allowing users to duplicate any SL goods without paying creators for them.

Some SL residents chafe at the amount of control Linden Lab retains over Second Life. Substantial changes to the environment are often unilaterally imposed, and some business owners have planned for conditions in SL that changed without warning and with no recompense. (This writer is unaware of any form of insurance that would cover, say, massive terra re-forming in SL.) Also, SL requires proprietary software, and upgrades are mandatory, though free.

Meanwhile, ownership leads to commerce leads to taxation -- maybe. A congressional committee has been examining the issues incumbent on taxing virtual economies. That report is pending, but at least one committee member is opposed to taxing SL revenues.