In the comics, the Insidious Six are called the Sinister Six. The Fox Kids network had the name changed to "Insidious Six" because they thought the name "Sinister Six" sounded too menacing for a cartoon series for children. Only two of the members of the team from the comics make it into the team's roster: Doctor Octopus and Mysterio. Shocker, Chameleon, Scorpion and The Rhino are the remaining four on the original animated team, while Sandman, Electro, Kraven the Hunter, and The Vulture were the remaining four on the original comic team. Both teams had an original member replaced (The Vulture who joins the Six to take Mysterio's place in Season 5 while Hobgoblin joins the Six to take Kraven's place in the comics)
All I cared about was taking care of number one. Me.
The episodes shown in syndication of the Jetix line-up feature a shortened opening credit sequence that shows clips from all 5 seasons. However, Season Two episodes have their original intro.
After the terrorist attacks on the USA of 11 September 2001, ABCFamily heavily edited the episode "Day of the Chameleon" to remove the World Trade Center, buildings, parts of the NY skyline, a helicopter crashing into a building, as well as exploding and falling to the ground below, among other shots... making the first scene virtually implausible to comprehend as it was originally intended. Dialogue was re-looped to match the new, shorter, version. Also, some production credits from the episode are missing as well, due to their being on screen during the omitted footage.