Yeah. DOS attacks can cripple sites, so they have to take precaution. lets suppose sajha has capability of giving out a 100 handshakes in 1 min. If you shake its hand all 100 times in 1 min, no one else will be allowed to do the same :D So u would be denying service to other users (like me) who want to access Sajha's service (handshake) :) Corny explanation but hope it helped.


 Don't open too many tabs, and you should be fine. At the most, you'll be banned for 20 mins.

Its nothing to worry about unless ure actually planning a Denial Of Service attack. :D