Did any group in Russia oppose Crimean annexation?
If Yes, I have a few more questions:
- Were they political groups or non-political groups?
- What was their objective: only to oppose Putin, or, to show solidarity with Ukraine?
- Were they arrested?
Yes, there were plenty such groups within the Russian opposition. The largest of those is the Yabloko party. Their presidential candidate in 2018 stated that:
Any form of forceful intervention in the internal affairs of Ukraine, as well as the incitement and propaganda of war should be stopped. Commitments to Ukraine's territorial integrity and respect by Russia of its international obligations should be declared at the highest state level.
The party was likewise opposed to the invasion of Crimea back in 2014. To answer your other questions:
Where they political groups or non-political groups?
The annexation of Crimea is inherently a political question, so this question doesn't make sense.
What was their objective: only to oppose Putin, or, to show solidarity with Ukraine?
Different opposition groups within Russia have different motivations, there isn't a single explanation to their actions.
Were they arrested?
Most were not arrested, for example Yavlinskiy openly expressed his opposition to the annexation for several years now and wasn't arrested.
Were they political groups or non-political groups?
Both. Yabloko were perhaps the largest official political party that openly opposed the annexation. Ilya Ponomarev(from the Just Russia party) was the only duma(senate) member who openly opposed the annexation, but his views were not collectively supported by the party he was representing. Navalny also expressed opposition to the annexation of Crimea, but did note that realistically he does not expect it to be returned to Ukraine any time soon.
Political parties aside, there was certainly a strong backlash against the annexation and a number of protests took place in the country, though they were not strong enough to stop or revert it. Марш Мира that took place in Moscow in 2014, for instance, had over 25000 participants, most of which were simple citizens and not active party members.
What was their objective: only to oppose Putin, or, to show solidarity with Ukraine?
I'm not aware of any major attempts to garner voters by such claims (and to be honest, with the current views that would be tantamount to political suicide, unless you're trying to muscle in on Navalny's and Yabloko's voters). In case of Yabloko for instance, it fits the existing party's pro-peace pro-EU agenda, although there is no denying that them openly condemning the annexation had brought them new followers.
From my personal observations of the 2014 peace protests, to most people attending them it was a way to express their anger, confusion and frustration with the ivory tower government that pitted two neighbouring countries with strong ethnic, historical and family ties against each other. There were lots of banners blaming Putin and Единая Россия specifically, and yet many people had solidarity/peace signs or carried Ukrainian and Russian flags next to each other.
Were they arrested?
Some were, but that heavily depended on where and when they were protesting. The Peace March mentioned above was sanctioned by the local Moscow authorities and saw very few arrests despite the strong police and military presence. Some others, such as the spontaneous day 1 protests, were not, and had a number of participants brutally arrested by the police.
Generally, it appears that most arrests started happening after the annexation where people were for example reported for posts on social networks and put to trial for separatism.
Yes, pro-Western parties and groups like Yabloko, Just Russia, groups around Navalny (Progress Party) opposed Crimea rejoining Russian Federation.
Their reasons were mostly to please their masters and financiers in the West, in process they lost lot of support among Russians, because Russian public has generally diametrically opposite opinion about Crimea than West .
Of course they were not arrested, they had every right to express their opinion according to Russian laws. Secretly I think Putin was quite pleased to let them shoot their own feet with such unpopular stance on this issue.
Yes, there are such groups. The two major factions who oppose the illegal annexation of Crimea have the following agendas:
There are Russian officials who have openly proposed to buy out Crimea.
One of those is Irina Khakamada, a member of "State Duma" of Russia and a leader of a "political party". In her interview to Radio Liberty (YouTube, transcript, both in Russian) she claimed that she suggested buying Crimea "even before Miloš Zeman did it in 2014".
To understand the idea, here's an English-language media outlet which seems to be highly favored to Russia. Its article dated back July 2014 and its title is self-explanatory: A simple solution to the crisis in Crimea: Let Russia buy it.
There is also a large faction of Russians who demanded "showing off the force" to deter the world from helping Ukraine because of fear of the war escalated to other countries of Europe:
Back in 2008, a notorious "Russian magazine", founded by the Kremlin's "political technologist" Gleb Pavlovskij, has published an article called Operation Clockwork Orange written by a self-styled "political scientist" Igor Zhadan. This article contained a pretty much detailed plan of a full-scale armed invasion to Ukraine and nuclear bombardment of European countries.
When Pavolvskij learned that his "plan" was not implemented, he switched to criticizing Putin:
Putin Loses Levers of Control Over the Russia
Aleksandr Dugin, a Russian Neo-Nazi, a close Putin's advisor and ideologist spoke for armed invasion and annexation of Ukraine well ten years before it happened.
Needless to say, Zhirinovskij has also advocated for first nuclear strike (YouTube, in Russian).
- What was their objective: only to oppose Putin, or, to show solidarity with Ukraine?
- Where they arrested?
Both 'peace' and 'war' factions actually support the regime's agenda. Their apparent "controversy" exists merely to control and skillfully channel the different opinions among the Russian population.
Most obviously, none of they are oppressed in any way.
group
notindividual
. Coz, an individual doesn't carry much importance in national politics unless he is affiliated with a group.