Direcly from JIRA posting SVC-2911:

Sunday, August 24, 2pm, Second LIfe was closed to logins due to the following reason:

“Due to higher-than-usual load, logins to Second Life have been temporarily disabled.”

Fact: Second Life currently boasts over 20,000 sims. People are paying anywhere from $75 to $350 per sim per month in tier fees. At the time of Linden Lab shutting down logins, the concurrency was 67,335… which is a little over 3 people per sim.

Our group is paying over $1,200 per month in sim fees. When I can’t log in to service my own group due to inappropriate policy in handling a concurrency of 3 user per sim… we are not getting our money’s worth and neither is anyone else. We do not pay such high fees to have our group members blocked from logging in at 67,335 concurrrency

If Linden Lab is going to host 20,000+ sims, then it would follow the company needs to install the asset servers, support equipment and network bandwidth to handle the number of users those sims will require.