Did the Greasers or Socs ever cross territories without asking?

Most readers probably assume that this must true. Rival gang members are not likely to ask permission every single time they might cross the street from the west side to the east side of town or vice versa. This question is also made a bit more difficult because Hinton doesn't give readers an exhaustive list of what locations are in each gang's territory.
The trick is going to be finding interactions between Greasers and Socs where the reader knows that one gang is in the other gang's territory without permission. Chapter 7 is a good location for this kind of instance. Ponyboy and Two-Bit are walking to the hospital to see Johnny, and a blue Mustang follows them. There are some Socs in the car including Randy. Everybody eventually stops, and Ponyboy and Randy have a conversation. It's likely that Ponyboy is in Greaser territory since he left his own home to get to the hospital. This means that the Mustang with the Socs is in Greaser territory without permission since Ponyboy wasn't expecting the visit.
Chapter 11 is another good location for evidence for this question. Ponyboy is at home recovering from his concussion, and Randy comes to visit him. Ponyboy isn't expecting the visit, and Darry doesn't seem to know that Randy was planning on coming; therefore, I think the reader can assume that Randy is in Greaser territory unannounced and without express permission.