横行不法的英文：
to act illegally;
to act against law and reason

act是什么意思：
n. 行为，行动；法案；法令；一幕，段；装腔作势
v. 行动；扮演；假装；装作；起作用，见效；举动像

This is an act of depressing.
这是使人压抑的行为。

The act of disappointing.
使人失望的行为

We must act, we must act quickly.
我们必须行动，立即行动。

illegally是什么意思：
adv. 非法地

They are illegal immigrants.
他们是非法移民。

Illegal immigrants or workers are sometimes referred to as illegals.
非法移居的移民或工人有时也被称为非法移民。

It is illegal to drink underage in America.
在美国，未到年龄喝酒是违法的。

against是什么意思：
prep. 与...相反；对...不利；倚靠；以防；以...为背景；和...相比

It is against federal law to discriminate against blacks.
歧视黑人是违反联邦法律的。

She was drugged against the pain.
她服麻醉药止痛。

He informed against the drugpusher.
他告发了那个毒品贩。