From Mechwarrior Living Legends Wiki
Base Raping is possible, but highly discourage tactic of attacking enemy units within their base. It's generally considered as a tactic against fair play rules. Inversion of Base Raping is the Base Camping.
Base rape usually occurs when one team has significant disadvantage in amount of players or in players skill. Sometimes it's an effect of Team Stacking, or surprising attack of few units on enemy base. In any case - it's defined by prolonged attack on enemy base. or units within, often combined with destroying turrets, or sometimes even units entering enemy hangar and hunting Battle Armor in there. Firebombing the enemy base is also considered as Base Raping due to very high amount of damage given by this weapon and very low chances of defense against it.
Base raping differs though from attacks to units which return back to base for repairs after an engagement - such moves are occasionally considered as acceptable by the community. Base Raping also cannot occur in Terrain Control mode, as primary objective of it is to capture the enemy base.
Countering Base Rape
The probably simplest way is simply to ask enemy team for more space using public chat (default key: [Y] ).
Alternatively on maps that allow this try to spawn in different base. Most of maps without another base contain airfield, so going into air is also a possibility.
It's also possible to simply push back the attackers - for this it's required to pick best possible brawlers and exit the hangar in largest group available, focusing fire on a single target at a time.
Finally, on some servers, mostly these sponsored by Clans or Units, it's possible to ask for admin intervention or collect screenshots of players base-raping and post them on forum of the Unit.
History of Base Raping in MWLL
Unlike in the Crysis itself, the MWLL was never plagued by the Base Raping. Much longer time required to move between bases made such attempts more difficult, though still it occasionally happens even in most recent version.
Major issue was in version 0.2.0 when newly added Long Tom Artillery Tank could be used for effective bombardment of enemy hangars. Due to much higher damage than today it was capable of destroying almost any unit in a single shot. Due to this in version 0.3.0 the LAMS turrets were introduced, which are capable of taking down the enemy Long Tom projectiles.